diff options
Diffstat (limited to 'lib/libc/gen/err.3')
| -rw-r--r-- | lib/libc/gen/err.3 | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/lib/libc/gen/err.3 b/lib/libc/gen/err.3 new file mode 100644 index 0000000..468fd1f --- /dev/null +++ b/lib/libc/gen/err.3 @@ -0,0 +1,204 @@ +.\" Copyright (c) 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" From: @(#)err.3 8.1 (Berkeley) 6/9/93 +.\" $FreeBSD$ +.\" +.Dd Mar 6, 1999 +.Dt ERR 3 +.Os BSD 4 +.Sh NAME +.Nm err , +.Nm verr , +.Nm errc , +.Nm verrc , +.Nm errx , +.Nm verrx , +.Nm warn , +.Nm vwarn , +.Nm warnc , +.Nm vwarnc , +.Nm warnx , +.Nm vwarnx , +.Nm err_set_exit , +.Nm err_set_file +.Nd formatted error messages +.Sh SYNOPSIS +.Fd #include <err.h> +.Ft void +.Fn err "int eval" "const char *fmt" "..." +.Ft void +.Fn err_set_exit "void (*exitf)(int)" +.Ft void +.Fn err_set_file "void *vfp" +.Ft void +.Fn errc "int eval" "int code" "const char *fmt" "..." +.Ft void +.Fn errx "int eval" "const char *fmt" "..." +.Ft void +.Fn warn "const char *fmt" "..." +.Ft void +.Fn warnc "int code" "const char *fmt" "..." +.Ft void +.Fn warnx "const char *fmt" "..." +.Fd #include <stdarg.h> +.Ft void +.Fn verr "int eval" "const char *fmt" "va_list args" +.Ft void +.Fn verrc "int eval" "int code" "const char *fmt" "va_list args" +.Ft void +.Fn verrx "int eval" "const char *fmt" "va_list args" +.Ft void +.Fn vwarn "const char *fmt" "va_list args" +.Ft void +.Fn vwarnc "int code" "const char *fmt" "va_list args" +.Ft void +.Fn vwarnx "const char *fmt" "va_list args" +.Sh DESCRIPTION +The +.Fn err +and +.Fn warn +family of functions display a formatted error message on the standard +error output, or on another file specified using the +.Fn err_set_file +function. +In all cases, the last component of the program name, a colon character, +and a space are output. +If the +.Va fmt +argument is not NULL, the formatted error message is output. +In the case of the +.Fn errc , +.Fn verrc , +.Fn warnc , +and +.Fn vwarnc +functions, +the error message string affiliated with the +.Va code +argument is also output, +preceded by another colon and space if necessary. +In all cases, the output is followed by a newline character. +.Pp +The +.Fn err , +.Fn verr , +.Fn warn , +and +.Fn vwarn +functions use the global variable +.Va errno +rather than the +.Va code +argument of the +.Fn errc +family +.Pp +The +.Fn err , +.Fn verr , +.Fn errc , +.Fn verrc , +.Fn errx , +and +.Fn verrx +functions do not return, but exit with the value of the argument +.Fa eval . +The +.Fn err_set_exit +function can be used to specify a function which is called before +.Xr exit 3 +to perform any necessary cleanup; passing a null function pointer for +.Va exitf +resets the hook to do nothing. +The +.Fn err_set_file +function sets the output stream used by the other functions. +Its +.Va vfp +argument must be either a pointer to an open stream +(possibly already converted to void *) +or a null pointer +(in which case the output stream is set to standard error). +.Sh EXAMPLES +Display the current errno information string and exit: +.Bd -literal -offset indent +if ((p = malloc(size)) == NULL) + err(1, NULL); +if ((fd = open(file_name, O_RDONLY, 0)) == -1) + err(1, "%s", file_name); +.Ed +.Pp +Display an error message and exit: +.Bd -literal -offset indent +if (tm.tm_hour < START_TIME) + errx(1, "too early, wait until %s", start_time_string); +.Ed +.Pp +Warn of an error: +.Bd -literal -offset indent +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); +.Ed +.Pp +Warn of an error without using the global variable +.Va errno : +.Bd -literal -offset indent +error = my_function(); /* returns a value from <errno.h> */ +if (error != 0) + warnc(error, "my_function"); +.Ed +.Sh SEE ALSO +.Xr exit 3 , +.Xr strerror 3 +.Sh HISTORY +The +.Fn err +and +.Fn warn +functions first appeared in +.Bx 4.4 . +The +.Fn err_set_exit +and +.Fn err_set_file +functions first appeared in +.Fx 2.1 . +The +.Fn errc +and +.Fn warnc +functions first appeared in +.Fx 3.0 . |
