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36 .\" @(#)strerror.3 8.1 (Berkeley) 6/9/93
48 .Nd system error messages
54 .Fn perror "const char *string"
55 .Vt extern const char * const sys_errlist[] ;
56 .Vt extern const int sys_nerr ;
59 .Fn strerror "int errnum"
61 .Fn strerror_r "int errnum" "char *strerrbuf" "size_t buflen"
68 functions look up the error message string corresponding to an
73 function accepts an error number argument
75 and returns a pointer to the corresponding
80 function renders the same result into
84 characters and returns 0 upon success.
88 function finds the error message corresponding to the current
89 value of the global variable
92 and writes it, followed by a newline, to the
93 standard error file descriptor.
98 and does not point to the null character,
99 this string is prepended to the message
100 string and separated from it by
103 otherwise, only the error message string is printed.
105 If the error number is not recognized, these functions return an error message
107 .Dq Li "Unknown error:\ "
108 followed by the error number in decimal.
116 Error numbers recognized by this implementation fall in
122 If insufficient storage is provided in
126 to contain the error string,
132 will contain an error message that has been truncated and
134 terminated to fit the length specified by
137 The message strings can be accessed directly using the external
142 contains a count of the messages in
144 The use of these variables is deprecated;
148 should be used instead.
168 functions first appeared in
172 function was implemented in
175 .An Wes Peters Aq wes@FreeBSD.org .
177 For unknown error numbers, the
179 function will return its result in a static buffer which
180 may be overwritten by subsequent calls.
184 is missing a type-qualifier; it should actually be
187 Programs that use the deprecated
189 variable often fail to compile because they declare it