/**
* slibc — Yet another C library
* Copyright © 2015 Mattias Andrée (maandree@member.fsf.org)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <error.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <stddef.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
/**
* Print an error message with a detailed description, and optionally exit.
*
* This is a GNU extension.
*
* @param status The process will exit, with the function returning, with this
* exit status, unless it is zero. If zero, the process shall not exit.
* @param errnum The value of `errno` when the error occurred, zero if the a textual
* description of the error, further than that of `format`, shall not
* be printed.
* @param format Formatting-string for a detailed description of what happend.
* @param args Formatting-arguments for `format`.
*/
void error(int status, int errnum, const char* format, ...)
{
va_list args;
va_start(args, format);
verror_at_line(status, errnum, NULL, 0, format, args);
va_end(args);
}
/**
* Variant of `error` that uses `va_list` instead of variadic arguments.
*
* This is a slibc extension to the GNU extension `error`.
*
* @param status The process will exit, with the function returning, with this
* exit status, unless it is zero. If zero, the process shall not exit.
* @param errnum The value of `errno` when the error occurred, zero if the a textual
* description of the error, further than that of `format`, shall not
* be printed.
* @param format Formatting-string for a detailed description of what happend.
* @param args Formatting-arguments for `format`.
*/
void verror(int status, int errnum, const char* format, va_list args)
{
verror_at_line(status, errnum, NULL, 0, format, args);
}
/**
* Variant of `error` that prints the filename and the line
* number whence the error occurred.
*
* This is a GNU extension.
*
* @param status The process will exit, with the function returning, with this
* exit status, unless it is zero. If zero, the process shall not exit.
* @param errnum The value of `errno` when the error occurred, zero if the a textual
* description of the error, further than that of `format`, shall not
* be printed.
* @param filename The filename of the source code file where the error occurred.
* @param linenum The line number of in the source code file where the error occurred.
* @param format Formatting-string for a detailed description of what happend.
* @param args Formatting-arguments for `format`.
*/
void error_at_line(int status, int errnum, const char* filename,
unsigned int linenum, const char* format, ...)
{
va_list args;
va_start(args, format);
verror_at_line(status, errnum, filename, linenum, format, args);
va_end(args);
}
/**
* Variant of `verror` that prints the filename and the line
* number whence the error occurred.
*
* This is a slibc extension to the GNU extension `error_at_line`.
*
* @param status The process will exit, with the function returning, with this
* exit status, unless it is zero. If zero, the process shall not exit.
* @param errnum The value of `errno` when the error occurred, zero if the a textual
* description of the error, further than that of `format`, shall not
* be printed.
* @param filename The filename of the source code file where the error occurred.
* @param linenum The line number of in the source code file where the error occurred.
* @param format Formatting-string for a detailed description of what happend.
* @param args Formatting-arguments for `format`.
*/
void verror_at_line(int status, int errnum, const char* filename,
unsigned int linenum, const char* format, va_list args)
{
int tty = isatty(STDERR_FILENO);
void (*pname)(void) = error_print_progname;
static const char* last_filename = NULL;
static unsigned int last_linenum = 0;
static int last_errnum = 0;
if (error_one_per_line)
if ((last_filename == filename) && (last_linenum == linenum) && (last_errnum == errnum))
goto skip_print;
if (pname != NULL)
pname();
else
{
fflush(stdout);
fprintf(stderr, "%(\033[0;1;31m)%s%(\033[0m)",
tty, program_invocation_name, tty);
}
fprintf(stderr, "%(: %(\033[35m%)%s%(\033[0m%): %(\033[32m%)%u%(\033[0m%)%)%(: %s%)%(: %)",
filename != NULL, tty, filename, tty, tty, linenum, tty,
errnum != 0, strerror(errnum) /* TODO strerror is not MT-Safe */, format != NULL);
if (filename != NULL)
last_filename = filename, last_linenum = linenum, last_errnum = errnum;
vfprintf(stderr, format, args);
fprintf(stderr, "\n", program_invocation_name);
fflush(stderr);
skip_print:
error_message_count++; /* TODO lock around this */
if (status)
exit(status);
}
/**
* Counts the number of times `error` ( verror`) and
* `error_at_line` (`verror_at_line`) has returned.
* This variable is global and shared by all threads.
*
* This is a GNU extension.
*/
volatile unsigned int error_message_count = 0;
/**
* If set to non-zero (the default), `error_at_line`
* and `verror_at_line` restrict themself to only
* print an error the first time it appears. This
* is determined by the uniqueness of the combination
* of the values on `filename` and `linenum`. However
* it will forget the line the next time the function
* is called from a different line. This variable is
* global and shared by all threads. Has a slibc
* modification, `errnum` is also remembered, meaning
* if the error code is different (zero is considered
* an error code), the error is printed even if it
* occurred on the same line as the last time.
*
* This is a GNU extension.
*/
volatile int error_one_per_line = 1;
/**
* If not `NULL`, this function is used instead of
* flushing stdout and printing the process name to
* stderr, by `error` (`verror`) and `verror_at_line`
* (`verror_at_line`). This variable is global and
* shared by all threads.
*
* This is a GNU extension.
*/
void (*volatile error_print_progname)(void) = NULL;
