TRUNCATE(2)         RISC/os Reference Manual          TRUNCATE(2)



NAME
     truncate, ftruncate - truncate a file to a specified length

SYNOPSIS
     For -systype sysv and -systype bsd43:

     truncate(path, length)
     char *path;
     offt length;

     ftruncate(fd, length)
     int fd;
     offt length;

DESCRIPTION
     truncate causes the file named by path or referenced by fd
     to be truncated 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 speci-
     fies the error.

ERRORS
     truncate succeeds unless:

     [ENOTDIR]           A component of the path prefix is not a
                         directory.

     [EINVAL]            The pathname contains a character with
                         the high-order bit set.

     [ENAMETOOLONG]      A component of a pathname exceeded 255
                         characters, or an entire path name
                         exceeded 1023 characters.

     [ENOENT]            The named file does not exist.

     [EACCES]            Search permission is denied for a com-
                         ponent of the path prefix.

     [EACCES]            The named file is not writable by the
                         user.

     [ELOOP]             Too many symbolic links were encountered
                         in translating the pathname.

     [EISDIR]            The named file is a directory.

     [EROFS]             The named file resides on a read-only



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TRUNCATE(2)         RISC/os Reference Manual          TRUNCATE(2)



                         file system.

     [ETXTBSY]           The file is a pure procedure (shared
                         text) file that is being executed.

     [EIO]               An I/O error occurred updating the
                         inode.

     [EFAULT]            path points outside the process's allo-
                         cated address space.

     ftruncate succeeds unless:

     [EBADF]             The fd is not a valid descriptor.

     [EINVAL]            The fd references a socket, not a file.

     [EINVAL]            The fd is not open for writing.

SEE ALSO
     open(2).

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

NOTE
     When these routines are used in a program which is compiled
     in -systype sysv, they are not resolved by libc.a.  See
     intro(3-SysV) for more information.

























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