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ERR(3)                      BSD Programmer's Manual                     ERR(3)

NAME
     err, verr, errx, verrx, warn, vwarn, warnx, vwarnx - formatted error mes-
     sages

SYNOPSIS
     #include <&lt;err.h>&gt;

     void
     err(int eval, const char *fmt, ...);

     void
     verr(int eval, const char *fmt, va_list args);

     void
     errx(int eval, const char *fmt, ...);

     void
     verrx(int eval, const char *fmt, va_list args);

     void
     warn(const char *fmt, ...);

     void
     vwarn(const char *fmt, va_list args);

     void
     warnx(const char *fmt, ...);

     void
     vwarnx(const char *fmt, va_list args);

DESCRIPTION
     The err() and warn() family of functions display a formatted error mes-
     sage 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 character, 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        June 9, 1993                                2