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fileno(3p) [centos man page]

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

PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the correspond- ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux. NAME
fileno - map a stream pointer to a file descriptor SYNOPSIS
#include <stdio.h> int fileno(FILE *stream); DESCRIPTION
The fileno() function shall return the integer file descriptor associated with the stream pointed to by stream. RETURN VALUE
Upon successful completion, fileno() shall return the integer value of the file descriptor associated with stream. Otherwise, the value -1 shall be returned and errno set to indicate the error. ERRORS
The fileno() function may fail if: EBADF The stream argument is not a valid stream. The following sections are informative. EXAMPLES
None. APPLICATION USAGE
None. RATIONALE
Without some specification of which file descriptors are associated with these streams, it is impossible for an application to set up the streams for another application it starts with fork() and exec. In particular, it would not be possible to write a portable version of the sh command interpreter (although there may be other constraints that would prevent that portability). FUTURE DIRECTIONS
None. SEE ALSO
Interaction of File Descriptors and Standard I/O Streams, fdopen(), fopen(), stdin(), the Base Definitions volume of IEEE Std 1003.1-2001, <stdio.h> COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol- ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. 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 http://www.opengroup.org/unix/online.html . IEEE
/The Open Group 2003 FILENO(3P)

Check Out this Related Man Page

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

PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the correspond- ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux. NAME
rewind - reset the file position indicator in a stream SYNOPSIS
#include <stdio.h> void rewind(FILE *stream); DESCRIPTION
The call: rewind(stream) shall be equivalent to: (void) fseek(stream, 0L, SEEK_SET) except that rewind() shall also clear the error indicator. Since rewind() does not return a value, an application wishing to detect errors should clear errno, then call rewind(), and if errno is non-zero, assume an error has occurred. RETURN VALUE
The rewind() function shall not return a value. ERRORS
Refer to fseek() with the exception of [EINVAL] which does not apply. The following sections are informative. EXAMPLES
None. APPLICATION USAGE
None. RATIONALE
None. FUTURE DIRECTIONS
None. SEE ALSO
fseek(), the Base Definitions volume of IEEE Std 1003.1-2001, <stdio.h> COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol- ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. 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 http://www.opengroup.org/unix/online.html . IEEE
/The Open Group 2003 REWIND(3P)
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