STDIN(3P)                 POSIX Programmer's Manual                STDIN(3P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior), or
       the interface may not be implemented on Linux.

NAME         top

       stderr, stdin, stdout — standard I/O streams

SYNOPSIS         top

       #include <stdio.h>

       extern FILE *stderr, *stdin, *stdout;

DESCRIPTION         top

       The functionality described on this reference page is aligned with
       the ISO C standard. Any conflict between the requirements described
       here and the ISO C standard is unintentional. This volume of
       POSIX.1‐2008 defers to the ISO C standard.

       A file with associated buffering is called a stream and is declared
       to be a pointer to a defined type FILE.  The fopen() function shall
       create certain descriptive data for a stream and return a pointer to
       designate the stream in all further transactions. Normally, there are
       three open streams with constant pointers declared in the <stdio.h>
       header and associated with the standard open files.

       At program start-up, three streams shall be predefined and need not
       be opened explicitly: standard input (for reading conventional
       input), standard output (for writing conventional output), and
       standard error (for writing diagnostic output). When opened, the
       standard error stream is not fully buffered; the standard input and
       standard output streams are fully buffered if and only if the stream
       can be determined not to refer to an interactive device.

       The following symbolic values in <unistd.h> define the file
       descriptors that shall be associated with the C-language stdin,
       stdout, and stderr when the application is started:

       STDIN_FILENO  Standard input value, stdin.  Its value is 0.

       STDOUT_FILENO Standard output value, stdout.  Its value is 1.

       STDERR_FILENO Standard error value, stderr.  Its value is 2.

       The stderr stream is expected to be open for reading and writing.

RETURN VALUE         top


ERRORS         top

       No errors are defined.

       The following sections are informative.

EXAMPLES         top




RATIONALE         top




SEE ALSO         top

       fclose(3p), feof(3p), ferror(3p), fileno(3p), fopen(3p), fprintf(3p),
       fread(3p), fscanf(3p), fseek(3p), getc(3p), gets(3p), popen(3p),
       putc(3p), puts(3p), read(3p), setbuf(3p), setvbuf(3p), tmpfile(3p),
       ungetc(3p), vfprintf(3p)

       The Base Definitions volume of POSIX.1‐2008, stdio.h(0p),

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) In the event of any discrepancy between this version and
       the original IEEE and The Open Group Standard, the original IEEE and
       The Open Group Standard is the referee document. The original
       Standard can be obtained online at .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see .

IEEE/The Open Group                 2013                           STDIN(3P)