postgresql/src/backend/port/strerror.c

/*
 * strerror - map error number to descriptive string
 *
 * This version is obviously somewhat Unix-specific.
 *
 * based on code by Henry Spencer
 * modified for ANSI by D'Arcy J.M. Cain
 */

#include		<string.h>
#include		<stdio.h>
#include		<errno.h>

extern const char *const sys_errlist[];
extern int		sys_nerr;

const char	   *
strerror(int errnum)
{
	static char		buf[24];

	if (errnum < 0 || errnum > sys_nerr)
	{
		sprintf(buf, "unknown error %d", errnum);
		return (buf);
	}

	return (sys_errlist[errnum]);
}