1perror(3C) Standard C Library Functions perror(3C)
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6 perror, errno - print system error messages
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9 #include <stdio.h>
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11 void perror(const char *s)
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14 #include <errno.h>
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16 int errno;
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20 The perror() function produces a message on the standard error output
21 (file descriptor 2) describing the last error encountered during a call
22 to a system or library function. The argument string s is printed, fol‐
23 lowed by a colon and a blank, followed by the message and a NEWLINE
24 character. If s is a null pointer or points to a null string, the
25 colon is not printed. The argument string should include the name of
26 the program that incurred the error. The error number is taken from the
27 external variable errno, which is set when errors occur but not cleared
28 when non-erroneous calls are made. See Intro(2).
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31 In the case of multithreaded applications, the -mt option must be spec‐
32 ified on the command line at compilation time (see threads(5)). When
33 the -mt option is specified, errno becomes a macro that enables each
34 thread to have its own errno. This errno macro can be used on either
35 side of the assignment as though it were a variable.
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38 Messages printed from this function are in the native language speci‐
39 fied by the LC_MESSAGES locale category. See setlocale(3C).
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42 See attributes(5) for descriptions of the following attributes:
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47 ┌─────────────────────────────┬─────────────────────────────┐
48 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
49 ├─────────────────────────────┼─────────────────────────────┤
50 │Interface Stability │Standard │
51 ├─────────────────────────────┼─────────────────────────────┤
52 │MT-Level │MT-Safe │
53 └─────────────────────────────┴─────────────────────────────┘
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56 Intro(2), fmtmsg(3C), gettext(3C), setlocale(3C), strerror(3C),
57 attributes(5), standards(5), threads(5)
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61SunOS 5.11 12 Jul 2007 perror(3C)