31 lines
1.1 KiB
Groff
31 lines
1.1 KiB
Groff
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NAME
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perror, errno, sys_errlist, sys_nerr - system error messages
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SYNTAX
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void perror (s)
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char *s;
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extern int errno;
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extern char *sys_errlist[ ];
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extern int sys_nerr;
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DESCRIPTION
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Perror produces a message on the standard error output,
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describing the last error encountered during a call to a
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system or library function. The argument string s is
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printed first, then a colon and a blank, then the message
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and a new-line. To be of most use, the argument string
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should include the name of the program that incurred the
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error. The error number is taken from the external variable
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errno, which is set when errors occur but not cleared when
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non-erroneous calls are made.
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To simplify variant formatting of messages, the array of
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message strings sys_errlist is provided; errno can be used
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as an index in this table to get the message string without
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the new-line. Sys_nerr is the largest message number
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provided for in the table; it should be checked because new
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error codes may be added to the system before they are added
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to the table.
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SEE ALSO
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intro(2).
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