CHMOD

Portability Function: Changes the access mode of a file.

Module: USE DFPORT

Syntax

result = CHMOD (name, mode)

name
(Input) Character*(*). Name of the file whose access mode is to be changed. Must have a single path.

mode
(Input) Character*(*). File permission: either Read, Write, or Execute. The mode parameter can be either symbolic or absolute. An absolute mode is specified with an octal number, consisting of any combination of the following permission bits ORed together:

Permission bit	Description	Action
4000	Set user ID on execution	Ignored; never true
2000	Set group ID on execution	Ignored; never true
1000	Sticky bit	Ignored; never true
0400	Read by owner	Ignored; always true
0200	Write by owner	Settable
0100	Execute by owner	Ignored; based on filename extension
0040, 0020, 0010	Read, Write, Execute by group	Ignored; assumes owner permissions
0004, 0002, 0001	Read, Write, Execute by others	Ignored; assumes owner permissions

The following regular expression represents a symbolic mode:

[ugoa]*[+-=] [rwxXst]* 

"[ugoa]*" is ignored. "[+ - =]" indicates the operation to carry out:

+	Add the permission
-	Remove the permission
=	Absolutely set the permission

"[rwxXst]*" indicates the permission to add, subtract, or set. Only "w" is significant and affects write permission. All other letters are ignored.

Results:

INTEGER(4). Zero if the mode was changed successfully; otherwise, an error code. Possible error codes are:

• ENOENT: The specified file was not found.
• EINVAL: The mode argument is invalid.
• EPERM: Permission denied; the file's mode cannot be changed.

Compatibility

CONSOLE STANDARD GRAPHICS QUICKWIN GRAPHICS WINDOWS DLL LIB

See Also: SETFILEACCESSQQ

Example

USE DFPORT
integer(4) I,Istatus
I = ACCESS ("DATAFILE.TXT", "w")
if (i) then
   ISTATUS = CHMOD ("datafile.txt", "[+w]")
end if
I = ACCESS ("DATAFILE.TXT","w")
print *, i