err(3) [bsd man page]
ERR(3) Library Functions Manual ERR(3) NAME
err, verr , errx , verrx , warn , vwarn , warnx , vwarnx - formatted error messages SYNOPSIS
void err(eval, fmt, ...) int eval; char *fmt; void verr(eval, fmt, args) int eval; char *fmt; va_list args; void errx(eval, fmt, ...) int eval; char *fmt; void verrx(eval, fmt, args) int eval char *fmt; va_list args; void warn(fmt, ...) char *fmt; void vwarn(fmt, args) char *fmt; va_list args; void warnx(fmt, ...) char *fmt; void vwarnx(fmt, args) char *fmt; va_list args; DESCRIPTION
The err and warn family of functions display a formatted error message on the standard error output. In all cases, the last component of the program name, a colon character, and a space are output. If the fmt argument is not NULL, the formatted error message, a colon charac- ter, and a space are output. In the case of the err, verr, warn, and vwarn functions, the error message string affiliated with the current value of the global variable errno is output. In all cases, the output is followed by a newline character. The err, verr, errx, and verrx functions do not return, but exit with the value of the argument eval. EXAMPLES
Display the current errno information string and exit: if ((p = malloc(size)) == NULL) err(1, NULL); if ((fd = open(file_name, O_RDONLY, 0)) == -1) err(1, "%s", file_name); Display an error message and exit: if (tm.tm_hour < START_TIME) errx(1, "too early, wait until %s", start_time_string); Warn of an error: if ((fd = open(raw_device, O_RDONLY, 0)) == -1) warnx("%s: %s: trying the block device", raw_device, strerror(errno)); if ((fd = open(block_device, O_RDONLY, 0)) == -1) err(1, "%s", block_device); SEE ALSO
strerror(3) HISTORY
The err and warn functions first appeared in 4.4BSD. 4th Berkeley Distribution February 3, 1995 ERR(3)
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ERR(3) BSD Library Functions Manual ERR(3) NAME
err, verr, errx, verrx, warn, vwarn, warnx, vwarnx, -- formatted error messages SYNOPSIS
#include <err.h> void err(int eval, const char *fmt, ...); void errx(int eval, const char *fmt, ...); void warn(const char *fmt, ...); void warnx(const char *fmt, ...); #include <stdarg.h> void verr(int eval, const char *fmt, va_list args); void verrx(int eval, const char *fmt, va_list args); void vwarn(const char *fmt, va_list args); void vwarnx(const char *fmt, va_list args); DESCRIPTION
The err() and warn() family of functions display a formatted error message on the standard error output. In all cases, the last component of the program name, a colon character, and a space are output. If the fmt argument is not NULL, the printf(3) -like formatted error message is output. The output is terminated by a newline character. The err(), verr(), warn(), and vwarn() functions append an error message obtained from strerror(3) based on a code or the global variable errno, preceded by another colon and space unless the fmt argument is NULL. The err(), verr(), warn(), and vwarn() functions use the global variable errno to look up the error message. The errx() and warnx() functions do not append an error message. The err(), verr(), errx(), and verrx() functions do not return, but exit with the value of the argument eval. EXAMPLES
Display the current errno information string and exit: if ((p = malloc(size)) == NULL) err(1, NULL); if ((fd = open(file_name, O_RDONLY, 0)) == -1) err(1, "%s", file_name); Display an error message and exit: if (tm.tm_hour < START_TIME) errx(1, "too early, wait until %s", start_time_string); Warn of an error: if ((fd = open(raw_device, O_RDONLY, 0)) == -1) warnx("%s: %s: trying the block device", raw_device, strerror(errno)); if ((fd = open(block_device, O_RDONLY, 0)) == -1) err(1, "%s", block_device); SEE ALSO
exit(3), printf(3), perror(3), strerror(3) HISTORY
The err() and warn() functions first appeared in 4.4BSD. BSD
March 6, 1999 BSD