NAME¶
error, error_at_line, error_message_count, error_one_per_line,
error_print_progname - glibc error reporting functions
SYNOPSIS¶
#include <error.h>
void error(int status, int errnum, const char *format, ...);
void error_at_line(int status, int errnum, const char *filename,
unsigned int linenum, const char *format, ...);
extern unsigned int error_message_count;
extern int error_one_per_line;
extern void (*error_print_progname) (void);
DESCRIPTION¶
error() is a general error-reporting function. It flushes
stdout,
and then outputs to
stderr the program name, a colon and a space, the
message specified by the
printf(3)-style format string
format,
and, if
errnum is nonzero, a second colon and a space followed by the
string given by
strerror(errnum). Any arguments required for
format should follow
format in the argument list. The output is
terminated by a newline character.
The program name printed by
error() is the value of the global variable
program_invocation_name(3).
program_invocation_name initially
has the same value as
main()'s
argv[0]. The value of this
variable can be modified to change the output of
error().
If
status has a nonzero value, then
error() calls
exit(3)
to terminate the program using the given value as the exit status.
The
error_at_line() function is exactly the same as
error(),
except for the addition of the arguments
filename and
linenum.
The output produced is as for
error(), except that after the program
name are written: a colon, the value of
filename, a colon, and the
value of
linenum. The preprocessor values
__LINE__ and
__FILE__ may be useful when calling
error_at_line(), but other
values can also be used. For example, these arguments could refer to a
location in an input file.
If the global variable
error_one_per_line is set nonzero, a sequence of
error_at_line() calls with the same value of
filename and
linenum will result in only one message (the first) being output.
The global variable
error_message_count counts the number of messages
that have been output by
error() and
error_at_line().
If the global variable
error_print_progname is assigned the address of a
function (i.e., is not NULL), then that function is called instead of
prefixing the message with the program name and colon. The function should
print a suitable string to
stderr.
These functions and variables are GNU extensions, and should not be used in
programs intended to be portable.
SEE ALSO¶
err(3),
errno(3),
exit(3),
perror(3),
program_invocation_name(3),
strerror(3)
COLOPHON¶
This page is part of release 3.74 of the Linux
man-pages project. A
description of the project, information about reporting bugs, and the latest
version of this page, can be found at
http://www.kernel.org/doc/man-pages/.
