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 perror(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_invoca-
       tion_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 sta-
       tus.

       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 3.25 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                                                        2006-04-25                                                   ERROR(3)