chsize()

change the size of a file

Synopsis:

#include <unistd.h>
int chsize( int filedes, long size );

Description:

The chsize() function changes the size of the file associated with filedes, by extending or truncating the file to the length specified by size. If the file needs to be extended, the file is padded with NULL ('\0') characters.

The chsize() function call ignores advisory locks that may have been set by the fcntl(), lock(), or locking() functions.

Returns:

0

Success.

-1

An error occurred; errno is set to indicate the error.

Errors:

EACCES

The specified file is locked against access.

EBADF

Invalid file descriptor, or the file is not opened for writing.

ENOSPC

There isn't enough space left on the device to extend the file.

Examples:

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>

void main()
  {
    int  filedes;

    filedes= open( "file", O_RDWR | O_CREAT,
        S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP );
    if( filedes!= -1 ) {
      if( chsize( filedes, 32 * 1024L ) != 0 ) {
          printf( "Error extending file\n" );
      }
      close( filedes);
    }
  }

Classification:

WATCOM

See also:

close(), creat(), errno, open()