Error processing
[Classification]
Standard library
[Syntax]
#include <stdio.h>
void perror(const char *s);
[Description]
This function outputs to stderr the error message that corresponds to global variable errno.
The message that is output is as follows.
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When s is not NULL
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fprintf(stderr, "%s:%s\n", s, s_fix);
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When s is NULL
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fprintf(stderr, "%s\n", s_fix);
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s_fix is as follows.
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When errno is EDOM
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"EDOM error"
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When errno is ERANGE
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"ERANGE error"
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When errno is 0
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"no error"
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Otherwise
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"error xxx" (xxx is abs (errno) % 1000)
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[Example]
#include <stdio.h>
#include <errno.h>
void func(double x) {
double d;
errno = 0;
d = exp(x);
if(errno)
perror("func1"); /*If a calculation exception is generated by exp
perror is called.*/
}
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