Chmod

Change file permission bits

Declaration

Source position: oldlinux.pp line 1398

Description

Chmod Sets the Mode bits of the file in Path to NewMode. Newmode can be specified by 'or'-ing the following:

S_ISUID

Set user ID on execution.

S_ISGID

Set Group ID on execution.

S_ISVTX

Set sticky bit.

S_IRUSR

Read by owner.

S_IWUSR

Write by owner.

S_IXUSR

Execute by owner.

S_IRGRP

Read by group.

S_IWGRP

Write by group.

S_IXGRP

Execute by group.

S_IROTH

Read by others.

S_IWOTH

Write by others.

S_IXOTH

Execute by others.

S_IRWXO

Read, write, execute by others.

S_IRWXG

Read, write, execute by groups.

S_IRWXU

Read, write, execute by user.

Errors

Errors are returned in LinuxError.

sys_eperm

The effective UID doesn't match the ownership of the file, and is not zero. Owner or group were not specified correctly.

sys_eaccess

One of the directories in Path has no search (=execute) permission.

sys_enoent

A directory entry in Path does not exist or is a symbolic link pointing to a non-existent directory.

sys_enomem

Insufficient kernel memory.

sys_erofs

The file is on a read-only filesystem.

sys_eloop

Path has a reference to a circular symbolic link, i.e. a symbolic link, whose expansion points to itself.

See also

Example

Program Example23;

{ Program to demonstrate the Chmod function. }

Uses oldlinux;

Var F : Text;

begin
  { Create a file }
  Assign (f,'testex21');
  Rewrite (F);
  Writeln (f,'#!/bin/sh');
  Writeln (f,'echo Some text for this file');
  Close (F);
  { Octal() makes the correct number from a
    number that LOOKS octal }
  Chmod ('testex21',octal (777));
  { File is now executable  }
  execl ('./testex21');
end.