1 .\" $NetBSD: make.1,v 1.273 2018/05/27 01:14:51 christos Exp $
3 .\" Copyright (c) 1990, 1993
4 .\" The Regents of the University of California. All rights reserved.
6 .\" Redistribution and use in source and binary forms, with or without
7 .\" modification, are permitted provided that the following conditions
9 .\" 1. Redistributions of source code must retain the above copyright
10 .\" notice, this list of conditions and the following disclaimer.
11 .\" 2. Redistributions in binary form must reproduce the above copyright
12 .\" notice, this list of conditions and the following disclaimer in the
13 .\" documentation and/or other materials provided with the distribution.
14 .\" 3. Neither the name of the University nor the names of its contributors
15 .\" may be used to endorse or promote products derived from this software
16 .\" without specific prior written permission.
18 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 .\" from: @(#)make.1 8.4 (Berkeley) 3/19/94
37 .Nd maintain program dependencies
56 is a program designed to simplify the maintenance of other programs.
57 Its input is a list of specifications as to the files upon which programs
58 and other files depend.
61 makefile option is given,
67 in order to find the specifications.
70 exists, it is read (see
73 This manual page is intended as a reference document only.
74 For a more thorough description of
76 and makefiles, please refer to
77 .%T "PMake \- A Tutorial" .
80 will prepend the contents of the
82 environment variable to the command line arguments before parsing them.
84 The options are as follows:
87 Try to be backwards compatible by executing a single shell per command and
88 by executing the commands to make the sources of a dependency line in sequence.
92 before reading the makefiles or doing anything else.
95 options are specified, each is interpreted relative to the previous one:
96 .Fl C Pa / Fl C Pa etc
102 to be 1, in the global context.
104 Turn on debugging, and specify which portions of
106 are to print debugging information.
107 Unless the flags are preceded by
109 they are added to the
111 environment variable and will be processed by any child make processes.
112 By default, debugging information is printed to standard error,
113 but this can be changed using the
116 The debugging output is always unbuffered; in addition, if debugging
117 is enabled but debugging output is not directed to standard output,
118 then the standard output is line buffered.
120 is one or more of the following:
123 Print all possible debugging information;
124 equivalent to specifying all of the debugging flags.
126 Print debugging information about archive searching and caching.
128 Print debugging information about current working directory.
130 Print debugging information about conditional evaluation.
132 Print debugging information about directory searching and caching.
134 Print debugging information about failed commands and targets.
135 .It Ar F Ns Oo Sy \&+ Oc Ns Ar filename
136 Specify where debugging output is written.
137 This must be the last flag, because it consumes the remainder of
139 If the character immediately after the
143 then the file will be opened in append mode;
144 otherwise the file will be overwritten.
149 then debugging output will be written to the
150 standard output or standard error output file descriptors respectively
153 option has no effect).
154 Otherwise, the output will be written to the named file.
155 If the file name ends
159 is replaced by the pid.
161 Print debugging information about loop evaluation.
163 Print the input graph before making anything.
165 Print the input graph after making everything, or before exiting
168 Print the input graph before exiting on error.
170 Print debugging information about running multiple shells.
172 Print commands in Makefiles regardless of whether or not they are prefixed by
174 or other "quiet" flags.
175 Also known as "loud" behavior.
177 Print debugging information about "meta" mode decisions about targets.
179 Print debugging information about making targets, including modification
182 Don't delete the temporary command scripts created when running commands.
183 These temporary scripts are created in the directory
186 environment variable, or in
190 is unset or set to the empty string.
191 The temporary scripts are created by
193 and have names of the form
196 This can create many files in
202 Print debugging information about makefile parsing.
204 Print debugging information about suffix-transformation rules.
206 Print debugging information about target list maintenance.
210 option to print raw values of variables, overriding the default behavior
212 .Va .MAKE.EXPAND_VARIABLES .
214 Print debugging information about variable assignment.
216 Run shell commands with
218 so the actual commands are printed as they are executed.
221 Specify that environment variables override macro assignments within
224 Specify a makefile to read instead of the default
230 standard input is read.
231 Multiple makefiles may be specified, and are read in the order specified.
232 .It Fl I Ar directory
233 Specify a directory in which to search for makefiles and included makefiles.
234 The system makefile directory (or directories, see the
236 option) is automatically included as part of this list.
238 Ignore non-zero exit of shell commands in the makefile.
239 Equivalent to specifying
241 before each command line in the makefile.
245 be specified by the user.
249 option is in use in a recursive build, this option is passed by a make
250 to child makes to allow all the make processes in the build to
251 cooperate to avoid overloading the system.
253 Specify the maximum number of jobs that
255 may have running at any one time.
256 The value is saved in
258 Turns compatibility mode off, unless the
260 flag is also specified.
261 When compatibility mode is off, all commands associated with a
262 target are executed in a single shell invocation as opposed to the
263 traditional one shell invocation per line.
264 This can break traditional scripts which change directories on each
265 command invocation and then expect to start with a fresh environment
267 It is more efficient to correct the scripts rather than turn backwards
270 Continue processing after errors are encountered, but only on those targets
271 that do not depend on the target whose creation caused the error.
272 .It Fl m Ar directory
273 Specify a directory in which to search for sys.mk and makefiles included
275 .Ao Ar file Ac Ns -style
279 option can be used multiple times to form a search path.
280 This path will override the default system include path: /usr/share/mk.
281 Furthermore the system include path will be appended to the search path used
283 .Qo Ar file Qc Ns -style
284 include statements (see the
288 If a file or directory name in the
292 environment variable) starts with the string
296 will search for the specified file or directory named in the remaining part
297 of the argument string.
298 The search starts with the current directory of
299 the Makefile and then works upward towards the root of the file system.
300 If the search is successful, then the resulting directory replaces the
305 If used, this feature allows
307 to easily search in the current source tree for customized sys.mk files
312 Display the commands that would have been executed, but do not
313 actually execute them unless the target depends on the .MAKE special
316 Display the commands which would have been executed, but do not
317 actually execute any of them; useful for debugging top-level makefiles
318 without descending into subdirectories.
320 Do not execute any commands, but exit 0 if the specified targets are
321 up-to-date and 1, otherwise.
323 Do not use the built-in rules specified in the system makefile.
325 Do not echo any commands as they are executed.
326 Equivalent to specifying
328 before each command line in the makefile.
329 .It Fl T Ar tracefile
333 append a trace record to
335 for each job started and completed.
337 Rather than re-building a target as specified in the makefile, create it
338 or update its modification time to make it appear up-to-date.
342 Do not build any targets.
343 Multiple instances of this option may be specified;
344 the variables will be printed one per line,
345 with a blank line for each null or undefined variable.
346 The value printed is extracted from the global context after all
347 makefiles have been read.
348 By default, the raw variable contents (which may
349 include additional unexpanded variable references) are shown.
354 then the value will be recursively expanded to its complete resultant
355 text before printing.
356 The expanded value will also be printed if
357 .Va .MAKE.EXPAND_VARIABLES
361 option has not been used to override it.
362 Note that loop-local and target-local variables, as well as values
363 taken temporarily by global variables during makefile processing, are
364 not accessible via this option.
367 debug mode can be used to see these at the cost of generating
368 substantial extraneous output.
372 but the variable is always expanded to its complete value.
374 Treat any warnings during makefile parsing as errors.
376 Print entering and leaving directory messages, pre and post processing.
378 Don't export variables passed on the command line to the environment
380 Variables passed on the command line are still exported
383 environment variable.
384 This option may be useful on systems which have a small limit on the
385 size of command arguments.
386 .It Ar variable=value
387 Set the value of the variable
391 Normally, all values passed on the command line are also exported to
392 sub-makes in the environment.
395 flag disables this behavior.
396 Variable assignments should follow options for POSIX compatibility
397 but no ordering is enforced.
400 There are seven different types of lines in a makefile: file dependency
401 specifications, shell commands, variable assignments, include statements,
402 conditional directives, for loops, and comments.
404 In general, lines may be continued from one line to the next by ending
405 them with a backslash
407 The trailing newline character and initial whitespace on the following
408 line are compressed into a single space.
409 .Sh FILE DEPENDENCY SPECIFICATIONS
410 Dependency lines consist of one or more targets, an operator, and zero
412 This creates a relationship where the targets
415 and are usually created from them.
416 The exact relationship between the target and the source is determined
417 by the operator that separates them.
418 The three operators are as follows:
421 A target is considered out-of-date if its modification time is less than
422 those of any of its sources.
423 Sources for a target accumulate over dependency lines when this operator
425 The target is removed if
429 Targets are always re-created, but not until all sources have been
430 examined and re-created as necessary.
431 Sources for a target accumulate over dependency lines when this operator
433 The target is removed if
437 If no sources are specified, the target is always re-created.
438 Otherwise, a target is considered out-of-date if any of its sources has
439 been modified more recently than the target.
440 Sources for a target do not accumulate over dependency lines when this
442 The target will not be removed if
447 Targets and sources may contain the shell wildcard values
458 may only be used as part of the final
459 component of the target or source, and must be used to describe existing
463 need not necessarily be used to describe existing files.
464 Expansion is in directory order, not alphabetically as done in the shell.
466 Each target may have associated with it one or more lines of shell
468 used to create the target.
469 Each of the lines in this script
471 be preceded by a tab.
472 (For historical reasons, spaces are not accepted.)
473 While targets can appear in many dependency lines if desired, by
474 default only one of these rules may be followed by a creation
478 operator is used, however, all rules may include scripts and the
479 scripts are executed in the order found.
481 Each line is treated as a separate shell command, unless the end of
482 line is escaped with a backslash
484 in which case that line and the next are combined.
485 .\" The escaped newline is retained and passed to the shell, which
486 .\" normally ignores it.
487 .\" However, the tab at the beginning of the following line is removed.
488 If the first characters of the command are any combination of
493 the command is treated specially.
496 causes the command not to be echoed before it is executed.
499 causes the command to be executed even when
502 This is similar to the effect of the .MAKE special source,
503 except that the effect can be limited to a single line of a script.
506 in compatibility mode
507 causes any non-zero exit status of the command line to be ignored.
511 is run in jobs mode with
513 the entire script for the target is fed to a
514 single instance of the shell.
515 In compatibility (non-jobs) mode, each command is run in a separate process.
516 If the command contains any shell meta characters
517 .Pq Ql #=|^(){};&<>*?[]:$`\e\en
518 it will be passed to the shell; otherwise
520 will attempt direct execution.
521 If a line starts with
523 and the shell has ErrCtl enabled then failure of the command line
524 will be ignored as in compatibility mode.
527 affects the entire job;
528 the script will stop at the first command line that fails,
529 but the target will not be deemed to have failed.
531 Makefiles should be written so that the mode of
533 operation does not change their behavior.
534 For example, any command which needs to use
538 without potentially changing the directory for subsequent commands
539 should be put in parentheses so it executes in a subshell.
540 To force the use of one shell, escape the line breaks so as to make
541 the whole script one command.
543 .Bd -literal -offset indent
544 avoid-chdir-side-effects:
545 @echo Building $@ in `pwd`
546 @(cd ${.CURDIR} && ${MAKE} $@)
549 ensure-one-shell-regardless-of-mode:
550 @echo Building $@ in `pwd`; \e
551 (cd ${.CURDIR} && ${MAKE} $@); \e
561 before executing any targets, each child process
562 starts with that as its current working directory.
563 .Sh VARIABLE ASSIGNMENTS
564 Variables in make are much like variables in the shell, and, by tradition,
565 consist of all upper-case letters.
566 .Ss Variable assignment modifiers
567 The five operators that can be used to assign values to variables are as
571 Assign the value to the variable.
572 Any previous value is overridden.
574 Append the value to the current value of the variable.
576 Assign the value to the variable if it is not already defined.
578 Assign with expansion, i.e. expand the value before assigning it
580 Normally, expansion is not done until the variable is referenced.
582 References to undefined variables are
585 This can cause problems when variable modifiers are used.
587 Expand the value and pass it to the shell for execution and assign
588 the result to the variable.
589 Any newlines in the result are replaced with spaces.
592 Any white-space before the assigned
594 is removed; if the value is being appended, a single space is inserted
595 between the previous contents of the variable and the appended value.
597 Variables are expanded by surrounding the variable name with either
602 and preceding it with
605 If the variable name contains only a single letter, the surrounding
606 braces or parentheses are not required.
607 This shorter form is not recommended.
609 If the variable name contains a dollar, then the name itself is expanded first.
610 This allows almost arbitrary variable names, however names containing dollar,
611 braces, parenthesis, or whitespace are really best avoided!
613 If the result of expanding a variable contains a dollar sign
615 the string is expanded again.
617 Variable substitution occurs at three distinct times, depending on where
618 the variable is being used.
621 Variables in dependency lines are expanded as the line is read.
623 Variables in shell commands are expanded when the shell command is
627 loop index variables are expanded on each loop iteration.
628 Note that other variables are not expanded inside loops so
629 the following example code:
630 .Bd -literal -offset indent
644 .Bd -literal -offset indent
649 Because while ${a} contains
651 after the loop is executed, ${b}
656 since after the loop completes ${j} contains
660 The four different classes of variables (in order of increasing precedence)
663 .It Environment variables
664 Variables defined as part of
668 Variables defined in the makefile or in included makefiles.
669 .It Command line variables
670 Variables defined as part of the command line.
672 Variables that are defined specific to a certain target.
675 Local variables are all built in and their values vary magically from
677 It is not currently possible to define new local variables.
678 The seven local variables are as follows:
679 .Bl -tag -width ".ARCHIVE" -offset indent
681 The list of all sources for this target; also known as
684 The name of the archive file; also known as
687 In suffix-transformation rules, the name/path of the source from which the
688 target is to be transformed (the
690 source); also known as
692 It is not defined in explicit rules.
694 The name of the archive member; also known as
697 The list of sources for this target that were deemed out-of-date; also
701 The file prefix of the target, containing only the file portion, no suffix
702 or preceding directory components; also known as
704 The suffix must be one of the known suffixes declared with
706 or it will not be recognized.
708 The name of the target; also known as
710 For compatibility with other makes this is an alias for
712 in archive member rules.
724 are permitted for backward
725 compatibility with historical makefiles and legacy POSIX make and are
728 Variants of these variables with the punctuation followed immediately by
734 are legacy forms equivalent to using the
739 These forms are accepted for compatibility with
741 makefiles and POSIX but are not recommended.
743 Four of the local variables may be used in sources on dependency lines
744 because they expand to the proper value for each target on the line.
751 .Ss Additional built-in variables
754 sets or knows about the following variables:
755 .Bl -tag -width .MAKEOVERRIDES
761 expands to a single dollar
764 The list of all targets encountered in the Makefile.
766 Makefile parsing, lists only those targets encountered thus far.
768 A path to the directory where
771 Refer to the description of
774 .It Va .INCLUDEDFROMDIR
775 The directory of the file this Makefile was included from.
776 .It Va .INCLUDEDFROMFILE
777 The filename of the file this Makefile was included from.
788 The preferred variable to use is the environment variable
790 because it is more compatible with other versions of
792 and cannot be confused with the special target with the same name.
793 .It Va .MAKE.ALWAYS_PASS_JOB_QUEUE
796 whether to pass the descriptors of the job token queue
797 even if the target is not tagged with
801 for backwards compatability with
804 .It Va .MAKE.DEPENDFILE
805 Names the makefile (default
807 from which generated dependencies are read.
808 .It Va .MAKE.EXPAND_VARIABLES
809 A boolean that controls the default behavior of the
812 If true, variable values printed with
814 are fully expanded; if false, the raw variable contents (which may
815 include additional unexpanded variable references) are shown.
816 .It Va .MAKE.EXPORTED
817 The list of variables exported by
823 .It Va .MAKE.JOB.PREFIX
828 then output for each target is prefixed with a token
830 the first part of which can be controlled via
831 .Va .MAKE.JOB.PREFIX .
834 is empty, no token is printed.
837 .Li .MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
838 would produce tokens like
839 .Ql ---make[1234] target ---
840 making it easier to track the degree of parallelism being achieved.
842 The environment variable
844 may contain anything that
848 Anything specified on
850 command line is appended to the
852 variable which is then
853 entered into the environment for all programs which
857 The recursion depth of
859 The initial instance of
861 will be 0, and an incremented value is put into the environment
862 to be seen by the next generation.
863 This allows tests like:
864 .Li .if ${.MAKE.LEVEL} == 0
865 to protect things which should only be evaluated in the initial instance of
867 .It Va .MAKE.MAKEFILE_PREFERENCE
868 The ordered list of makefile names
875 .It Va .MAKE.MAKEFILES
876 The list of makefiles read by
878 which is useful for tracking dependencies.
879 Each makefile is recorded only once, regardless of the number of times read.
881 Processed after reading all makefiles.
882 Can affect the mode that
885 It can contain a number of keywords:
886 .Bl -hang -width missing-filemon=bf.
896 into "meta" mode, where meta files are created for each target
897 to capture the command run, the output generated and if
899 is available, the system calls which are of interest to
901 The captured output can be very useful when diagnosing errors.
902 .It Pa curdirOk= Ar bf
905 will not create .meta files in
907 This can be overridden by setting
909 to a value which represents True.
910 .It Pa missing-meta= Ar bf
913 is True, then a missing .meta file makes the target out-of-date.
914 .It Pa missing-filemon= Ar bf
917 is True, then missing filemon data makes the target out-of-date.
922 For debugging, it can be useful to include the environment
925 If in "meta" mode, print a clue about the target being built.
926 This is useful if the build is otherwise running silently.
927 The message printed the value of:
928 .Va .MAKE.META.PREFIX .
930 Some makefiles have commands which are simply not stable.
931 This keyword causes them to be ignored for
932 determining whether a target is out of date in "meta" mode.
938 is True, when a .meta file is created, mark the target
941 .It Va .MAKE.META.BAILIWICK
942 In "meta" mode, provides a list of prefixes which
943 match the directories controlled by
945 If a file that was generated outside of
947 but within said bailiwick is missing,
948 the current target is considered out-of-date.
949 .It Va .MAKE.META.CREATED
950 In "meta" mode, this variable contains a list of all the meta files
952 If not empty, it can be used to trigger processing of
953 .Va .MAKE.META.FILES .
954 .It Va .MAKE.META.FILES
955 In "meta" mode, this variable contains a list of all the meta files
956 used (updated or not).
957 This list can be used to process the meta files to extract dependency
959 .It Va .MAKE.META.IGNORE_PATHS
960 Provides a list of path prefixes that should be ignored;
961 because the contents are expected to change over time.
962 The default list includes:
963 .Ql Pa /dev /etc /proc /tmp /var/run /var/tmp
964 .It Va .MAKE.META.IGNORE_PATTERNS
965 Provides a list of patterns to match against pathnames.
966 Ignore any that match.
967 .It Va .MAKE.META.IGNORE_FILTER
968 Provides a list of variable modifiers to apply to each pathname.
969 Ignore if the expansion is an empty string.
970 .It Va .MAKE.META.PREFIX
971 Defines the message printed for each meta file updated in "meta verbose" mode.
972 The default value is:
973 .Dl Building ${.TARGET:H:tA}/${.TARGET:T}
974 .It Va .MAKEOVERRIDES
975 This variable is used to record the names of variables assigned to
976 on the command line, so that they may be exported as part of
978 This behavior can be disabled by assigning an empty value to
979 .Ql Va .MAKEOVERRIDES
981 Extra variables can be exported from a makefile
982 by appending their names to
983 .Ql Va .MAKEOVERRIDES .
985 is re-exported whenever
986 .Ql Va .MAKEOVERRIDES
988 .It Va .MAKE.PATH_FILEMON
993 support, this is set to the path of the device node.
994 This allows makefiles to test for this support.
999 The parent process-id of
1001 .It Va .MAKE.SAVE_DOLLARS
1002 value should be a boolean that controls whether
1004 are preserved when doing
1007 The default is false, for backwards compatibility.
1008 Set to true for compatability with other makes.
1013 per normal evaluation rules.
1014 .It Va MAKE_PRINT_VAR_ON_ERROR
1017 stops due to an error, it sets
1018 .Ql Va .ERROR_TARGET
1019 to the name of the target that failed,
1021 to the commands of the failed target,
1022 and in "meta" mode, it also sets
1027 .Ql Va .ERROR_META_FILE
1028 to the path of the meta file (if any) describing the failed target.
1029 It then prints its name and the value of
1031 as well as the value of any variables named in
1032 .Ql Va MAKE_PRINT_VAR_ON_ERROR .
1034 This variable is simply assigned a newline character as its value.
1035 This allows expansions using the
1037 modifier to put a newline between
1038 iterations of the loop rather than a space.
1039 For example, the printing of
1040 .Ql Va MAKE_PRINT_VAR_ON_ERROR
1041 could be done as ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.
1043 A path to the directory where the targets are built.
1044 Its value is determined by trying to
1046 to the following directories in order and using the first match:
1049 .Ev ${MAKEOBJDIRPREFIX}${.CURDIR}
1052 .Ql Ev MAKEOBJDIRPREFIX
1053 is set in the environment or on the command line.)
1059 is set in the environment or on the command line.)
1061 .Ev ${.CURDIR} Ns Pa /obj. Ns Ev ${MACHINE}
1063 .Ev ${.CURDIR} Ns Pa /obj
1065 .Pa /usr/obj/ Ns Ev ${.CURDIR}
1070 Variable expansion is performed on the value before it's used,
1071 so expressions such as
1072 .Dl ${.CURDIR:S,^/usr/src,/var/obj,}
1074 This is especially useful with
1078 may be modified in the makefile via the special target
1084 to the specified directory if it exists, and set
1088 to that directory before executing any targets.
1091 A path to the directory of the current
1095 The basename of the current
1100 are both set only while the
1103 If you want to retain their current values, assign them to a variable
1104 using assignment with expansion:
1107 A variable that represents the list of directories that
1109 will search for files.
1110 The search list should be updated using the target
1112 rather than the variable.
1114 Alternate path to the current directory.
1118 to the canonical path given by
1120 However, if the environment variable
1122 is set and gives a path to the current directory, then
1129 This behavior is disabled if
1130 .Ql Ev MAKEOBJDIRPREFIX
1133 contains a variable transform.
1135 is set to the value of
1137 for all programs which
1141 The list of targets explicitly specified on the command line, if any.
1145 lists of directories that
1147 will search for files.
1148 The variable is supported for compatibility with old make programs only,
1153 .Ss Variable modifiers
1154 Variable expansion may be modified to select or modify each word of the
1157 is white-space delimited sequence of characters).
1158 The general format of a variable expansion is as follows:
1160 .Dl ${variable[:modifier[:...]]}
1162 Each modifier begins with a colon,
1163 which may be escaped with a backslash
1166 A set of modifiers can be specified via a variable, as follows:
1168 .Dl modifier_variable=modifier[:...]
1169 .Dl ${variable:${modifier_variable}[:...]}
1171 In this case the first modifier in the modifier_variable does not
1172 start with a colon, since that must appear in the referencing
1174 If any of the modifiers in the modifier_variable contain a dollar sign
1176 these must be doubled to avoid early expansion.
1178 The supported modifiers are:
1181 Replaces each word in the variable with its suffix.
1183 Replaces each word in the variable with everything but the last component.
1184 .It Cm \&:M Ns Ar pattern
1185 Select only those words that match
1187 The standard shell wildcard characters
1194 The wildcard characters may be escaped with a backslash
1196 As a consequence of the way values are split into words, matched,
1197 and then joined, a construct like
1199 will normalize the inter-word spacing, removing all leading and
1200 trailing space, and converting multiple consecutive spaces
1203 .It Cm \&:N Ns Ar pattern
1204 This is identical to
1206 but selects all words which do not match
1209 Order every word in variable alphabetically.
1211 reverse order use the
1213 combination of modifiers.
1215 Randomize words in variable.
1216 The results will be different each time you are referring to the
1217 modified variable; use the assignment with expansion
1219 to prevent such behavior.
1221 .Bd -literal -offset indent
1222 LIST= uno due tre quattro
1223 RANDOM_LIST= ${LIST:Ox}
1224 STATIC_RANDOM_LIST:= ${LIST:Ox}
1227 @echo "${RANDOM_LIST}"
1228 @echo "${RANDOM_LIST}"
1229 @echo "${STATIC_RANDOM_LIST}"
1230 @echo "${STATIC_RANDOM_LIST}"
1232 may produce output similar to:
1233 .Bd -literal -offset indent
1240 Quotes every shell meta-character in the variable, so that it can be passed
1241 safely to the shell.
1243 Quotes every shell meta-character in the variable, and also doubles
1245 characters so that it can be passed
1246 safely through recursive invocations of
1248 This is equivalent to:
1249 .Sq \&:S/\e\&$/&&/g:Q .
1251 Replaces each word in the variable with everything but its suffix.
1252 .It Cm \&:range[=count]
1253 The value is an integer sequence representing the words of the original
1254 value, or the supplied
1256 .It Cm \&:gmtime[=utc]
1257 The value is a format string for
1263 value is not provided or is 0, the current time is used.
1265 Compute a 32-bit hash of the value and encode it as hex digits.
1266 .It Cm \&:localtime[=utc]
1267 The value is a format string for
1273 value is not provided or is 0, the current time is used.
1275 Attempt to convert variable to an absolute path using
1277 if that fails, the value is unchanged.
1279 Converts variable to lower-case letters.
1280 .It Cm \&:ts Ns Ar c
1281 Words in the variable are normally separated by a space on expansion.
1282 This modifier sets the separator to the character
1286 is omitted, then no separator is used.
1287 The common escapes (including octal numeric codes), work as expected.
1289 Converts variable to upper-case letters.
1291 Causes the value to be treated as a single word
1292 (possibly containing embedded white space).
1296 Causes the value to be treated as a sequence of
1297 words delimited by white space.
1301 .It Cm \&:S No \&/ Ar old_string No \&/ Ar new_string No \&/ Op Cm 1gW
1303 Modify the first occurrence of
1305 in the variable's value, replacing it with
1309 is appended to the last slash of the pattern, all occurrences
1310 in each word are replaced.
1313 is appended to the last slash of the pattern, only the first word
1317 is appended to the last slash of the pattern,
1318 then the value is treated as a single word
1319 (possibly containing embedded white space).
1325 is anchored at the beginning of each word.
1328 ends with a dollar sign
1330 it is anchored at the end of each word.
1341 Any character may be used as a delimiter for the parts of the modifier
1343 The anchoring, ampersand and delimiter characters may be escaped with a
1347 Variable expansion occurs in the normal fashion inside both
1351 with the single exception that a backslash is used to prevent the expansion
1354 not a preceding dollar sign as is usual.
1356 .It Cm \&:C No \&/ Ar pattern No \&/ Ar replacement No \&/ Op Cm 1gW
1360 modifier is just like the
1362 modifier except that the old and new strings, instead of being
1363 simple strings, are an extended regular expression (see
1371 Normally, the first occurrence of the pattern
1373 in each word of the value is substituted with
1377 modifier causes the substitution to apply to at most one word; the
1379 modifier causes the substitution to apply to as many instances of the
1382 as occur in the word or words it is found in; the
1384 modifier causes the value to be treated as a single word
1385 (possibly containing embedded white space).
1390 are orthogonal; the former specifies whether multiple words are
1391 potentially affected, the latter whether multiple substitutions can
1392 potentially occur within each affected word.
1400 are subjected to variable expansion before being parsed as
1401 regular expressions.
1403 Replaces each word in the variable with its last component.
1405 Remove adjacent duplicate words (like
1408 .It Cm \&:\&? Ar true_string Cm \&: Ar false_string
1410 If the variable name (not its value), when parsed as a .if conditional
1411 expression, evaluates to true, return as its value the
1413 otherwise return the
1415 Since the variable name is used as the expression, \&:\&? must be the
1416 first modifier after the variable name itself - which will, of course,
1417 usually contain variable expansions.
1418 A common error is trying to use expressions like
1419 .Dl ${NUMBERS:M42:?match:no}
1420 which actually tests defined(NUMBERS),
1421 to determine is any words match "42" you need to use something like:
1422 .Dl ${"${NUMBERS:M42}" != \&"\&":?match:no} .
1423 .It Ar :old_string=new_string
1426 style variable substitution.
1427 It must be the last modifier specified.
1432 do not contain the pattern matching character
1434 then it is assumed that they are
1435 anchored at the end of each word, so only suffixes or entire
1436 words may be replaced.
1444 Variable expansion occurs in the normal fashion inside both
1448 with the single exception that a backslash is used to prevent the
1449 expansion of a dollar sign
1451 not a preceding dollar sign as is usual.
1453 .It Cm \&:@ Ar temp Cm @ Ar string Cm @
1455 This is the loop expansion mechanism from the OSF Development
1456 Environment (ODE) make.
1459 loops expansion occurs at the time of
1463 to each word in the variable and evaluate
1465 The ODE convention is that
1467 should start and end with a period.
1469 .Dl ${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}
1471 However a single character variable is often more readable:
1472 .Dl ${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}
1474 Save the current variable value in
1478 for later reference.
1480 .Bd -literal -offset indent
1481 M_cmpv.units = 1 1000 1000000
1482 M_cmpv = S,., ,g:_:range:@i@+ $${_:[-$$i]} \&\\
1483 \\* $${M_cmpv.units:[$$i]}@:S,^,expr 0 ,1:sh
1485 .Dv .if ${VERSION:${M_cmpv}} < ${3.1.12:L:${M_cmpv}}
1490 is used to save the result of the
1492 modifier which is later referenced using the index values from
1494 .It Cm \&:U Ns Ar newval
1495 If the variable is undefined
1498 If the variable is defined, the existing value is returned.
1499 This is another ODE make feature.
1500 It is handy for setting per-target CFLAGS for instance:
1501 .Dl ${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
1502 If a value is only required if the variable is undefined, use:
1503 .Dl ${VAR:D:Unewval}
1504 .It Cm \&:D Ns Ar newval
1505 If the variable is defined
1509 The name of the variable is the value.
1511 The path of the node which has the same name as the variable
1513 If no such node exists or its path is null, then the
1514 name of the variable is used.
1515 In order for this modifier to work, the name (node) must at least have
1516 appeared on the rhs of a dependency.
1518 .It Cm \&:\&! Ar cmd Cm \&!
1520 The output of running
1524 If the variable is non-empty it is run as a command and the output
1525 becomes the new value.
1526 .It Cm \&::= Ns Ar str
1527 The variable is assigned the value
1530 This modifier and its variations are useful in
1531 obscure situations such as wanting to set a variable when shell commands
1533 These assignment modifiers always expand to
1534 nothing, so if appearing in a rule line by themselves should be
1535 preceded with something to keep
1541 helps avoid false matches with the
1545 modifier and since substitution always occurs the
1547 form is vaguely appropriate.
1548 .It Cm \&::?= Ns Ar str
1551 but only if the variable does not already have a value.
1552 .It Cm \&::+= Ns Ar str
1556 .It Cm \&::!= Ns Ar cmd
1557 Assign the output of
1560 .It Cm \&:\&[ Ns Ar range Ns Cm \&]
1561 Selects one or more words from the value,
1562 or performs other operations related to the way in which the
1563 value is divided into words.
1565 Ordinarily, a value is treated as a sequence of words
1566 delimited by white space.
1567 Some modifiers suppress this behavior,
1568 causing a value to be treated as a single word
1569 (possibly containing embedded white space).
1570 An empty value, or a value that consists entirely of white-space,
1571 is treated as a single word.
1572 For the purposes of the
1574 modifier, the words are indexed both forwards using positive integers
1575 (where index 1 represents the first word),
1576 and backwards using negative integers
1577 (where index \-1 represents the last word).
1581 is subjected to variable expansion, and the expanded result is
1582 then interpreted as follows:
1583 .Bl -tag -width index
1586 Selects a single word from the value.
1588 .It Ar start Ns Cm \&.. Ns Ar end
1589 Selects all words from
1596 selects all words from the second word to the last word.
1601 then the words are output in reverse order.
1604 selects all the words from last to first.
1607 Causes subsequent modifiers to treat the value as a single word
1608 (possibly containing embedded white space).
1609 Analogous to the effect of
1618 Causes subsequent modifiers to treat the value as a sequence of words
1619 delimited by white space.
1620 Analogous to the effect of
1625 Returns the number of words in the value.
1628 .Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS
1629 Makefile inclusion, conditional structures and for loops reminiscent
1630 of the C programming language are provided in
1632 All such structures are identified by a line beginning with a single
1636 Files are included with either
1637 .Cm \&.include Aq Ar file
1639 .Cm \&.include Pf \*q Ar file Ns \*q .
1640 Variables between the angle brackets or double quotes are expanded
1641 to form the file name.
1642 If angle brackets are used, the included makefile is expected to be in
1643 the system makefile directory.
1644 If double quotes are used, the including makefile's directory and any
1645 directories specified using the
1647 option are searched before the system
1649 For compatibility with other versions of
1651 .Ql include file ...
1654 If the include statement is written as
1658 then errors locating and/or opening include files are ignored.
1660 If the include statement is written as
1662 not only are errors locating and/or opening include files ignored,
1663 but stale dependencies within the included file will be ignored
1665 .Va .MAKE.DEPENDFILE .
1667 Conditional expressions are also preceded by a single dot as the first
1668 character of a line.
1669 The possible conditionals are as follows:
1671 .It Ic .error Ar message
1672 The message is printed along with the name of the makefile and line number,
1676 .It Ic .export Ar variable ...
1677 Export the specified global variable.
1678 If no variable list is provided, all globals are exported
1679 except for internal variables (those that start with
1681 This is not affected by the
1683 flag, so should be used with caution.
1684 For compatibility with other
1687 .Ql export variable=value
1690 Appending a variable name to
1692 is equivalent to exporting a variable.
1693 .It Ic .export-env Ar variable ...
1696 except that the variable is not appended to
1697 .Va .MAKE.EXPORTED .
1698 This allows exporting a value to the environment which is different from that
1702 .It Ic .export-literal Ar variable ...
1705 except that variables in the value are not expanded.
1706 .It Ic .info Ar message
1707 The message is printed along with the name of the makefile and line number.
1708 .It Ic .undef Ar variable
1709 Un-define the specified global variable.
1710 Only global variables may be un-defined.
1711 .It Ic .unexport Ar variable ...
1714 The specified global
1716 will be removed from
1717 .Va .MAKE.EXPORTED .
1718 If no variable list is provided, all globals are unexported,
1722 .It Ic .unexport-env
1723 Unexport all globals previously exported and
1724 clear the environment inherited from the parent.
1725 This operation will cause a memory leak of the original environment,
1726 so should be used sparingly.
1729 being 0, would make sense.
1730 Also note that any variables which originated in the parent environment
1731 should be explicitly preserved if desired.
1733 .Bd -literal -offset indent
1734 .Li .if ${.MAKE.LEVEL} == 0
1741 Would result in an environment containing only
1743 which is the minimal useful environment.
1746 will also be pushed into the new environment.
1747 .It Ic .warning Ar message
1748 The message prefixed by
1750 is printed along with the name of the makefile and line number.
1751 .It Ic \&.if Oo \&! Oc Ns Ar expression Op Ar operator expression ...
1752 Test the value of an expression.
1753 .It Ic .ifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1754 Test the value of a variable.
1755 .It Ic .ifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1756 Test the value of a variable.
1757 .It Ic .ifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1758 Test the target being built.
1759 .It Ic .ifnmake Oo \&! Ns Oc Ar target Op Ar operator target ...
1760 Test the target being built.
1762 Reverse the sense of the last conditional.
1763 .It Ic .elif Oo \&! Ns Oc Ar expression Op Ar operator expression ...
1768 .It Ic .elifdef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1773 .It Ic .elifndef Oo \&! Oc Ns Ar variable Op Ar operator variable ...
1778 .It Ic .elifmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1783 .It Ic .elifnmake Oo \&! Oc Ns Ar target Op Ar operator target ...
1789 End the body of the conditional.
1794 may be any one of the following:
1795 .Bl -tag -width "Cm XX"
1801 of higher precedence than
1807 will only evaluate a conditional as far as is necessary to determine
1809 Parentheses may be used to change the order of evaluation.
1810 The boolean operator
1812 may be used to logically negate an entire
1814 It is of higher precedence than
1819 may be any of the following:
1820 .Bl -tag -width defined
1822 Takes a variable name as an argument and evaluates to true if the variable
1825 Takes a target name as an argument and evaluates to true if the target
1826 was specified as part of
1828 command line or was declared the default target (either implicitly or
1831 before the line containing the conditional.
1833 Takes a variable, with possible modifiers, and evaluates to true if
1834 the expansion of the variable would result in an empty string.
1836 Takes a file name as an argument and evaluates to true if the file exists.
1837 The file is searched for on the system search path (see
1840 Takes a target name as an argument and evaluates to true if the target
1843 Takes a target name as an argument and evaluates to true if the target
1844 has been defined and has commands associated with it.
1848 may also be an arithmetic or string comparison.
1849 Variable expansion is
1850 performed on both sides of the comparison, after which the integral
1851 values are compared.
1852 A value is interpreted as hexadecimal if it is
1853 preceded by 0x, otherwise it is decimal; octal numbers are not supported.
1854 The standard C relational operators are all supported.
1856 variable expansion, either the left or right hand side of a
1860 operator is not an integral value, then
1861 string comparison is performed between the expanded
1863 If no relational operator is given, it is assumed that the expanded
1864 variable is being compared against 0 or an empty string in the case
1865 of a string comparison.
1869 is evaluating one of these conditional expressions, and it encounters
1870 a (white-space separated) word it doesn't recognize, either the
1874 expression is applied to it, depending on the form of the conditional.
1882 expression is applied.
1883 Similarly, if the form is
1889 expression is applied.
1891 If the conditional evaluates to true the parsing of the makefile continues
1893 If it evaluates to false, the following lines are skipped.
1894 In both cases this continues until a
1900 For loops are typically used to apply a set of rules to a list of files.
1901 The syntax of a for loop is:
1903 .Bl -tag -compact -width Ds
1904 .It Ic \&.for Ar variable Oo Ar variable ... Oc Ic in Ar expression
1911 is evaluated, it is split into words.
1912 On each iteration of the loop, one word is taken and assigned to each
1916 are substituted into the
1918 inside the body of the for loop.
1919 The number of words must come out even; that is, if there are three
1920 iteration variables, the number of words provided must be a multiple
1923 Comments begin with a hash
1925 character, anywhere but in a shell
1926 command line, and continue to the end of an unescaped new line.
1927 .Sh SPECIAL SOURCES (ATTRIBUTES)
1928 .Bl -tag -width .IGNOREx
1930 Target is never out of date, but always execute commands anyway.
1932 Ignore any errors from the commands associated with this target, exactly
1933 as if they all were preceded by a dash
1935 .\" .It Ic .INVISIBLE
1940 Mark all sources of this target as being up-to-date.
1942 Execute the commands associated with this target even if the
1946 options were specified.
1947 Normally used to mark recursive
1950 Create a meta file for the target, even if it is flagged as
1955 Usage in conjunction with
1957 is the most likely case.
1958 In "meta" mode, the target is out-of-date if the meta file is missing.
1960 Do not create a meta file for the target.
1961 Meta files are also not created for
1968 Ignore differences in commands when deciding if target is out of date.
1969 This is useful if the command contains a value which always changes.
1970 If the number of commands change, though, the target will still be out of date.
1971 The same effect applies to any command line that uses the variable
1973 which can be used for that purpose even when not otherwise needed or desired:
1974 .Bd -literal -offset indent
1976 skip-compare-for-some:
1977 @echo this will be compared
1978 @echo this will not ${.OODATE:M.NOMETA_CMP}
1979 @echo this will also be compared
1984 pattern suppresses any expansion of the unwanted variable.
1986 Do not search for the target in the directories specified by
1991 selects the first target it encounters as the default target to be built
1992 if no target was specified.
1993 This source prevents this target from being selected.
1995 If a target is marked with this attribute and
1997 can't figure out how to create it, it will ignore this fact and assume
1998 the file isn't needed or already exists.
2001 correspond to an actual file; it is always considered to be out of date,
2002 and will not be created with the
2005 Suffix-transformation rules are not applied to
2011 is interrupted, it normally removes any partially made targets.
2012 This source prevents the target from being removed.
2017 Do not echo any of the commands associated with this target, exactly
2018 as if they all were preceded by an at sign
2021 Turn the target into
2024 When the target is used as a source for another target, the other target
2025 acquires the commands, sources, and attributes (except for
2029 If the target already has commands, the
2031 target's commands are appended
2038 target commands to the target.
2042 appears in a dependency line, the sources that precede it are
2043 made before the sources that succeed it in the line.
2044 Since the dependents of files are not made until the file itself
2045 could be made, this also stops the dependents being built unless they
2046 are needed for another branch of the dependency tree.
2059 the output is always
2065 The ordering imposed by
2067 is only relevant for parallel makes.
2070 Special targets may not be included with other targets, i.e. they must be
2071 the only target specified.
2072 .Bl -tag -width .BEGINx
2074 Any command lines attached to this target are executed before anything
2079 rule for any target (that was used only as a
2082 can't figure out any other way to create.
2083 Only the shell script is used.
2086 variable of a target that inherits
2089 to the target's own name.
2090 .It Ic .DELETE_ON_ERROR
2091 If this target is present in the makefile, it globally causes make to
2092 delete targets whose commands fail.
2093 (By default, only targets whose commands are interrupted during
2094 execution are deleted.
2095 This is the historical behavior.)
2096 This setting can be used to help prevent half-finished or malformed
2097 targets from being left around and corrupting future rebuilds.
2099 Any command lines attached to this target are executed after everything
2102 Any command lines attached to this target are executed when another target fails.
2105 variable is set to the target that failed.
2107 .Ic MAKE_PRINT_VAR_ON_ERROR .
2109 Mark each of the sources with the
2112 If no sources are specified, this is the equivalent of specifying the
2118 is interrupted, the commands for this target will be executed.
2120 If no target is specified when
2122 is invoked, this target will be built.
2124 This target provides a way to specify flags for
2126 when the makefile is used.
2127 The flags are as if typed to the shell, though the
2131 .\" XXX: NOT YET!!!!
2132 .\" .It Ic .NOTPARALLEL
2133 .\" The named targets are executed in non parallel mode.
2134 .\" If no targets are
2135 .\" specified, then all targets are executed in non parallel mode.
2139 attribute to any specified sources.
2141 Disable parallel mode.
2145 for compatibility with other pmake variants.
2147 The source is a new value for
2153 to it and update the value of
2156 The named targets are made in sequence.
2157 This ordering does not add targets to the list of targets to be made.
2158 Since the dependents of a target do not get built until the target itself
2159 could be built, unless
2161 is built by another part of the dependency graph,
2162 the following is a dependency loop:
2168 The ordering imposed by
2170 is only relevant for parallel makes.
2171 .\" XXX: NOT YET!!!!
2172 .\" .It Ic .PARALLEL
2173 .\" The named targets are executed in parallel mode.
2174 .\" If no targets are
2175 .\" specified, then all targets are executed in parallel mode.
2177 The sources are directories which are to be searched for files not
2178 found in the current directory.
2179 If no sources are specified, any previously specified directories are
2181 If the source is the special
2183 target, then the current working
2184 directory is searched last.
2185 .It Ic .PATH. Ns Va suffix
2188 but applies only to files with a particular suffix.
2189 The suffix must have been previously declared with
2194 attribute to any specified sources.
2198 attribute to any specified sources.
2199 If no sources are specified, the
2201 attribute is applied to every
2206 will use to execute commands.
2207 The sources are a set of
2210 .Bl -tag -width hasErrCtls
2212 This is the minimal specification, used to select one of the built-in
2219 Specifies the path to the shell.
2221 Indicates whether the shell supports exit on error.
2223 The command to turn on error checking.
2225 The command to disable error checking.
2227 The command to turn on echoing of commands executed.
2229 The command to turn off echoing of commands executed.
2231 The output to filter after issuing the
2234 It is typically identical to
2237 The flag to pass the shell to enable error checking.
2239 The flag to pass the shell to enable command echoing.
2241 The string literal to pass the shell that results in a single newline
2242 character when used outside of any quoting characters.
2246 \&.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \e
2247 check="set \-e" ignore="set +e" \e
2248 echo="set \-v" quiet="set +v" filter="set +v" \e
2249 echoFlag=v errFlag=e newline="'\en'"
2254 attribute to any specified sources.
2255 If no sources are specified, the
2257 attribute is applied to every
2258 command in the file.
2260 This target gets run when a dependency file contains stale entries, having
2262 set to the name of that dependency file.
2264 Each source specifies a suffix to
2266 If no sources are specified, any previously specified suffixes are deleted.
2267 It allows the creation of suffix-transformation rules.
2273 cc \-o ${.TARGET} \-c ${.IMPSRC}
2278 uses the following environment variables, if they exist:
2284 .Ev MAKEOBJDIRPREFIX ,
2290 .Ev MAKEOBJDIRPREFIX
2293 may only be set in the environment or on the command line to
2295 and not as makefile variables;
2296 see the description of
2300 .Bl -tag -width /usr/share/mk -compact
2302 list of dependencies
2304 list of dependencies
2306 list of dependencies
2310 system makefile directory
2313 The basic make syntax is compatible between different versions of make;
2314 however the special variables, variable modifiers and conditionals are not.
2316 An incomplete list of changes in older versions of
2319 The way that .for loop variables are substituted changed after
2321 so that they still appear to be variable expansions.
2322 In particular this stops them being treated as syntax, and removes some
2323 obscure problems using them in .if statements.
2325 The way that parallel makes are scheduled changed in
2327 so that .ORDER and .WAIT apply recursively to the dependent nodes.
2328 The algorithms used may change again in the future.
2329 .Ss Other make dialects
2330 Other make dialects (GNU make, SVR4 make, POSIX make, etc.) do not
2331 support most of the features of
2333 as described in this manual.
2335 .Bl -bullet -offset indent
2341 declarations and most functionality pertaining to parallelization.
2342 (GNU make supports parallelization but lacks these features needed to
2343 control it effectively.)
2345 Directives, including for loops and conditionals and most of the
2346 forms of include files.
2347 (GNU make has its own incompatible and less powerful syntax for
2350 All built-in variables that begin with a dot.
2352 Most of the special sources and targets that begin with a dot,
2353 with the notable exception of
2359 Variable modifiers, except for the
2361 string substitution, which does not portably support globbing with
2363 and historically only works on declared suffixes.
2367 variable even in its short form; most makes support this functionality
2368 but its name varies.
2371 Some features are somewhat more portable, such as assignment with
2378 functionality is based on an older feature
2380 found in GNU make and many versions of SVR4 make; however,
2381 historically its behavior is too ill-defined (and too buggy) to rely
2388 variables are more or less universally portable, as is the
2391 Basic use of suffix rules (for files only in the current directory,
2392 not trying to chain transformations together, etc.) is also reasonably
2396 .Xr style.Makefile 5
2404 implementation is based on Adam De Boor's pmake program which was written
2405 for Sprite at Berkeley.
2406 It was designed to be a parallel distributed make running jobs on different
2407 machines using a daemon called
2410 Historically the target/dependency
2412 has been used to FoRCe rebuilding (since the target/dependency
2413 does not exist... unless someone creates an
2419 syntax is difficult to parse without actually acting of the data.
2420 For instance finding the end of a variable use should involve scanning each
2421 the modifiers using the correct terminator for each field.
2424 just counts {} and () in order to find the end of a variable expansion.
2426 There is no way of escaping a space character in a filename.