2 .\" The Regents of the University of California. All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
7 .\" 1. Redistributions of source code must retain the above copyright
8 .\" notice, this list of conditions and the following disclaimer.
9 .\" 2. Redistributions in binary form must reproduce the above copyright
10 .\" notice, this list of conditions and the following disclaimer in the
11 .\" documentation and/or other materials provided with the distribution.
12 .\" 4. Neither the name of the University nor the names of its contributors
13 .\" may be used to endorse or promote products derived from this software
14 .\" without specific prior written permission.
16 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
17 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 .\" @(#)pathconf.2 8.1 (Berkeley) 6/4/93
38 .Nd get configurable pathname variables
44 .Fn pathconf "const char *path" "int name"
46 .Fn lpathconf "const char *path" "int name"
48 .Fn fpathconf "int fd" "int name"
55 system calls provide a method for applications to determine the current
56 value of a configurable system limit or option variable associated
57 with a pathname or file descriptor.
65 argument is the name of a file or directory.
70 argument is an open file descriptor.
73 argument specifies the system variable to be queried.
74 Symbolic constants for each name value are found in the include file
81 except in the case where the named file is a symbolic link,
84 returns information about the link,
87 returns information about the file the link references.
89 The available values are as follows:
92 The maximum file link count.
94 The maximum number of bytes in terminal canonical input line.
96 The minimum maximum number of bytes for which space is available in
97 a terminal input queue.
99 The maximum number of bytes in a file name.
101 The maximum number of bytes in a pathname.
103 The maximum number of bytes which will be written atomically to a pipe.
104 .It Li _PC_CHOWN_RESTRICTED
105 Return 1 if appropriate privilege is required for the
107 system call, otherwise 0.
109 requires appropriate privilege in all cases, but this behavior was optional
110 in prior editions of the standard.
112 Return greater than zero if attempts to use pathname components longer than
116 error; otherwise, such components will be truncated to
119 requires the error in all cases, but this behavior was optional in prior
120 editions of the standard, and some
121 .No non- Ns Tn POSIX Ns -compliant
122 file systems do not support this behavior.
124 Returns the terminal character disabling value.
126 Return 1 if asynchronous I/O is supported, otherwise 0.
128 Returns 1 if prioritised I/O is supported for this file,
131 Returns 1 if synchronised I/O is supported for this file, otherwise 0.
132 .It Li _PC_ALLOC_SIZE_MIN
133 Minimum number of bytes of storage allocated for any portion of a file.
134 .It Li _PC_FILESIZEBITS
135 Number of bits needed to represent the maximum file size.
136 .It Li _PC_REC_INCR_XFER_SIZE
137 Recommended increment for file transfer sizes between
138 .Dv _PC_REC_MIN_XFER_SIZE
140 .Dv _PC_REC_MAX_XFER_SIZE .
141 .It Li _PC_REC_MAX_XFER_SIZE
142 Maximum recommended file transfer size.
143 .It Li _PC_REC_MIN_XFER_SIZE
144 Minimum recommended file transfer size.
145 .It Li _PC_REC_XFER_ALIGN
146 Recommended file transfer buffer alignment.
147 .It Li _PC_SYMLINK_MAX
148 Maximum number of bytes in a symbolic link.
149 .It Li _PC_ACL_EXTENDED
150 Returns 1 if an Access Control List (ACL) can be set on the specified
153 Returns 1 if an NFSv4 ACLs can be set on the specified
155 .It Li _PC_ACL_PATH_MAX
156 Maximum number of ACL entries per file.
157 .It Li _PC_CAP_PRESENT
158 Returns 1 if a capability state can be set on the specified file,
160 .It Li _PC_INF_PRESENT
161 Returns 1 if an information label can be set on the specified file,
163 .It Li _PC_MAC_PRESENT
164 Returns 1 if a Mandatory Access Control (MAC) label can be set on the
165 specified file, otherwise 0.
166 .It Li _PC_MIN_HOLE_SIZE
167 If a file system supports the reporting of holes (see
172 return a positive number that represents the minimum hole size returned in
174 The offsets of holes returned will be aligned to this same value.
175 A special value of 1 is returned if the file system does not specify the minimum
176 hole size but still reports holes.
183 is not successful, \-1 is returned and
185 is set appropriately.
186 Otherwise, if the variable is associated with functionality that does
187 not have a limit in the system, \-1 is returned and
190 Otherwise, the current variable value is returned.
192 If any of the following conditions occur, the
196 system calls shall return -1 and set
198 to the corresponding value.
205 The implementation does not support an association of the variable
206 name with the associated file.
215 A component of the path prefix is not a directory.
216 .It Bq Er ENAMETOOLONG
217 A component of a pathname exceeded
222 or an entire path name exceeded
226 The named file does not exist.
228 Search permission is denied for a component of the path prefix.
230 Too many symbolic links were encountered in translating the pathname.
232 An I/O error occurred while reading from or writing to the file system.
244 is not a valid open file descriptor.
246 An I/O error occurred while reading from or writing to the file system.
256 system calls first appeared in
260 system call first appeared in