ERROR(3)						     Linux Programmer's Manual							  ERROR(3)

NAME

       error, error_at_line, error_message_count, error_on_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.

CONFORMING TO

       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 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

GNU
								    2010-08-29								  ERROR(3)