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truncate(3p) — Linux manual page

TRUNCATE(3P)            POSIX Programmer's ManualTRUNCATE(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

       truncate — truncate a file to a specified length

SYNOPSIS        top

       #include <unistd.h>       int truncate(const char *path, off_tlength);

DESCRIPTION        top

       Thetruncate() function shall cause the regular file named bypath       to have a size which shall be equal tolength bytes.       If the file previously was larger thanlength, the extra data is       discarded. If the file was previously shorter thanlength, its       size is increased, and the extended area appears as if it were       zero-filled.       The application shall ensure that the process has write permission       for the file.       If the request would cause the file size to exceed the soft file       size limit for the process, the request shall fail and the       implementation shall generate the SIGXFSZ signal for the process.       Thetruncate() function shall not modify the file offset for any       open file descriptions associated with the file. Upon successful       completion,truncate() shall mark for update the last data       modification and last file status change timestamps of the file,       and the S_ISUID and S_ISGID bits of the file mode may be cleared.

RETURN VALUE        top

       Upon successful completion,truncate() shall return 0. Otherwise,       -1 shall be returned, anderrno set to indicate the error.

ERRORS        top

       Thetruncate() function shall fail if:EINTRA signal was caught during execution.EINVALThelength argument was less than 0.EFBIGorEINVAL              Thelength argument was greater than the maximum file size.EIOAn I/O error occurred while reading from or writing to a              file system.EACCESA component of the path prefix denies search permission, or              write permission is denied on the file.EISDIRThe named file is a directory.ELOOPA loop exists in symbolic links encountered during              resolution of thepath argument.ENAMETOOLONG              The length of a component of a pathname is longer than              {NAME_MAX}.ENOENTA component ofpath does not name an existing file orpath              is an empty string.ENOTDIR              A component of the path prefix names an existing file that              is neither a directory nor a symbolic link to a directory,              or thepath argument contains at least one non-<slash>              character and ends with one or more trailing <slash>              characters and the last pathname component names an              existing file that is neither a directory nor a symbolic              link to a directory.EROFSThe named file resides on a read-only file system.       Thetruncate() function may fail if:ELOOPMore than {SYMLOOP_MAX} symbolic links were encountered              during resolution of thepath argument.ENAMETOOLONG              The length of a pathname exceeds {PATH_MAX}, or pathname              resolution of a symbolic link produced an intermediate              result with a length that exceeds {PATH_MAX}.The following sections are informative.

EXAMPLES        top

       None.

APPLICATION USAGE        top

       None.

RATIONALE        top

       None.

FUTURE DIRECTIONS        top

       None.

SEE ALSO        top

open(3p)       The Base Definitions volume of POSIX.1‐2017,unistd.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                2017TRUNCATE(3P)

Pages that refer to this page:unistd.h(0p), ftruncate(3p)

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