TRUNCATE(2)                      System Calls                      TRUNCATE(2)

NAME

       truncate, ftruncate - truncate a file to a specified length

SYNOPSIS

       #include <unistd.h>

       int truncate (const char *path, off_t length);
       int ftruncate (int fd, off_t length);

DESCRIPTION

       truncate  causes the file named by path or referenced by fd to be trun‐
       cated to at most length bytes in size.   If  the  file  previously  was
       larger  than  this  size,  the extra data is lost.  With ftruncate, the
       file must be open for writing.

RETURN VALUES

       A value of 0 is returned if the call succeeds.  If the call fails a  -1
       is returned, and the global variable errno specifies the error.

SEE ALSO

       open(2)

BUGS

       The  GNO implementation of truncate requires that the file must be able
       to be opened for writing.  If this is not possible, truncate returns -1
       and sets errno.

       These calls should be generalized to allow ranges of bytes in a file to
       be discarded.

HISTORY

       The ftruncate function call appeared in 4.2BSD.



GNO                             24 January 1997                    TRUNCATE(2)