access
Prev File System Next

access

access — checks a file for various permissions.

Synopsis

access (filename, mode)

Arguments

filename

The name of a file on disk.

mode

The file mode to be tested. The legal modes are discussed below.

Returns

Zero is returned if the access mode is valid, otherwise -1 is returned and the errno is set.

Description

This function checks a file for the following permissions. Two or more permissions in bitwise OR combinations can be checked at one time.

  • R_OK  Test for read permission.

  • W_OK  Test for write permission.

  • X_OK  Test for execute permission.

  • F_OK  Test for existence of file.

The library "const/Filesys.lsp" must be required to use the constants listed above.

Example

Gamma> require_lisp("const/Filesys");
"/usr/cogent/lib/const/Filesys.lsp"
Gamma> system("touch /tmp/access_test");
0
Gamma> system("chmod a=rx /tmp/access_test");
0
Gamma> access("/tmp/access_test", R_OK|X_OK);
0
Gamma> access("/tmp/access_test", W_OK);
-1
Gamma>

See Also

is_busy, is_file, is_readable, is_writable, errno

Prev Up Next
absolute_path  Home  basename