ERR(3) BSD Library Functions Manual ERR(3)

NAME
     eerrrr, vveerrrr, eerrrrcc, vveerrrrcc, eerrrrxx, vveerrrrxx, wwaarrnn, vvwwaarrnn, wwaarrnncc, vvwwaarrnncc, wwaarrnnxx,
     vvwwaarrnnxx, eerrrrsseetteexxiitt, eerrrrsseettffiillee - formatted error messages

LLIIBBRRAARRYY
     Standard C Library (libc, -lc)

SYNOPSIS
     ##iinncclluuddee <>

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

     void
     eerrrrsseetteexxiitt(void (*exitf)(int));

     void
     eerrrrsseettffiillee(void *vfp);

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

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

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

     void
     wwaarrnncc(int code, const char *fmt, ...);

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

     ##iinncclluuddee <>

     void
     vveerrrr(int eval, const char *fmt, valist args);

     void
     vveerrrrcc(int eval, int code, const char *fmt, valist args);

     void
     vveerrrrxx(int eval, const char *fmt, valist args);

     void
     vvwwaarrnn(const char *fmt, valist args);

     void
     vvwwaarrnncc(int code, const char *fmt, valist args);

     void
     vvwwaarrnnxx(const char *fmt, valist args);

DESCRIPTION
     The eerrrr() and wwaarrnn() family of functions display a formatted error mes-
     sage on the standard error output, or on another file specified using the
     eerrrrsseettffiillee() function.  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 eerrrr(), eerrrrcc(), vveerrrr(), vveerrrrcc(), wwaarrnn(), wwaarrnncc(), vvwwaarrnn(), and
     vvwwaarrnncc() 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.

     In the case of the eerrrrcc(), vveerrrrcc(), wwaarrnncc(), and vvwwaarrnncc() functions, the
     code argument is used to look up the error message.

     The eerrrr(), vveerrrr(), wwaarrnn(), and vvwwaarrnn() functions use the global variable
     errno to look up the error message.

     The eerrrrxx() and wwaarrnnxx() functions do not append an error message.

     The eerrrr(), vveerrrr(), eerrrrcc(), vveerrrrcc(), eerrrrxx(), and vveerrrrxx() functions do not
     return, but exit with the value of the argument eval.  It is recommended
     that the standard values defined in sysexits(3) be used for the value of
     eval.  The eerrrrsseetteexxiitt() function can be used to specify a function
     which is called before exit(3) to perform any necessary cleanup; passing
     a null function pointer for exitf resets the hook to do nothing.  The
     eerrrrsseettffiillee() function sets the output stream used by the other func-
     tions.  Its vfp argument must be either a pointer to an open stream (pos-
     sibly already converted to void *) or a null pointer (in which case the
     output stream is set to standard error).

EEXXAAMMPPLLEESS
     Display the current errno information string and exit:

           if ((p = malloc(size)) == NULL)
                   err(1, NULL);
           if ((fd = open(filename, ORDONLY, 0)) == -1)
                   err(1, "%s", filename);

     Display an error message and exit:

           if (tm.tmhour < STARTTIME)
                   errx(1, "too early, wait until %s", starttimestring);

     Warn of an error:

           if ((fd = open(rawdevice, ORDONLY, 0)) == -1)
                   warnx("%s: %s: trying the block device",
                       rawdevice, strerror(errno));
           if ((fd = open(blockdevice, ORDONLY, 0)) == -1)
                   err(1, "%s", blockdevice);

     Warn of an error without using the global variable errno:

           error = myfunction();  /* returns a value from  */
           if (error != 0)
                   warnc(error, "myfunction");

SEE ALSO
     exit(3), fmtmsg(3), printf(3), strerror(3), sysexits(3)

HISTORY     The eerrrr() and wwaarrnn() functions first appeared in 4.4BSD.  The
     eerrrrsseetteexxiitt() and eerrrrsseettffiillee() functions first appeared in
     FreeBSD 2.1.  The eerrrrcc() and wwaarrnncc() functions first appeared in
     FreeBSD 3.0.

BSD                              March 6, 1999                             BSD