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ftell(3p) — Linux manual page

FTELL(3P)               POSIX Programmer's ManualFTELL(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

       ftell, ftello — return a file offset in a stream

SYNOPSIS        top

       #include <stdio.h>       long ftell(FILE *stream);       off_t ftello(FILE *stream);

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.1‐2017 defers to the ISO C standard.       Theftell() function shall obtain the current value of the file-       position indicator for the stream pointed to bystream.       Theftell() function shall not change the setting oferrno if       successful.       Theftello() function shall be equivalent toftell(), except that       the return value is of typeoff_tand theftello() function may       change the setting oferrno if successful.

RETURN VALUE        top

       Upon successful completion,ftell() andftello() shall return the       current value of the file-position indicator for the stream       measured in bytes from the beginning of the file.       Otherwise,ftell() andftello() shall return -1, and seterrno to       indicate the error.

ERRORS        top

       Theftell() andftello() functions shall fail if:EBADFThe file descriptor underlyingstream is not an open file              descriptor.EOVERFLOW              Forftell(), the current file offset cannot be represented              correctly in an object of typelong.EOVERFLOW              Forftello(), the current file offset cannot be represented              correctly in an object of typeoff_t.ESPIPEThe file descriptor underlyingstream is associated with a              pipe, FIFO, or socket.The following sections are informative.

EXAMPLES        top

       None.

APPLICATION USAGE        top

       None.

RATIONALE        top

       None.

FUTURE DIRECTIONS        top

       None.

SEE ALSO        top

Section 2.5,Standard I/O Streams,fgetpos(3p),fopen(3p),fseek(3p),lseek(3p)       The Base Definitions volume of POSIX.1‐2017,stdio.h(0p)

COPYRIGHT        top

       Portions of this text are reprinted and reproduced in electronic       form from IEEE Std 1003.1-2017, Standard for Information       Technology -- Portable Operating System Interface (POSIX), The       Open Group Base Specifications Issue 7, 2018 Edition, Copyright       (C) 2018 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 athttp://www.opengroup.org/unix/online.html .       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, seehttps://www.kernel.org/doc/man-pages/reporting_bugs.html .IEEE/The Open Group                2017FTELL(3P)

Pages that refer to this page:stdio.h(0p), fgetpos(3p), fseek(3p), fsetpos(3p)

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