( string filename, int mode )
Attempts to change the mode of the file specified by
filename to that given in
Note that mode is not automatically
assumed to be an octal value, so strings (such as "g+w") will
not work properly. To ensure the expected operation,
you need to prefix mode with a zero (0):
chmod("/somedir/somefile", 755); // decimal; probably incorrect
chmod("/somedir/somefile", "u+rwx,go+rx"); // string; incorrect
chmod("/somedir/somefile", 0755); // octal; correct value of mode
The mode parameter consists of three octal
number components specifying access restrictions for the owner,
the user group in which the owner is in, and to everybody else in
this order. One component can be computed by adding up the needed
permissions for that target user base. Number 1 means that you
grant execute rights, number 2 means that you make the file
writeable, number 4 means that you make the file readable. Add
up these numbers to specify needed rights. You can also read more
about modes on Unix systems with 'man 1 chmod' and 'man 2 chmod'.
// Read and write for owner, nothing for everybody else
// Read and write for owner, read for everybody else
// Everything for owner, read and execute for others
// Everything for owner, read and execute for owner's group
Returns TRUE on success or FALSE on failure.
The current user is the user under which PHP runs. It is
probably not the same user you use for normal shell or FTP
The mode can be changed only by user who owns the file on most systems.
Note: This function will not work on
remote files as the file to
be examined must be accessible via the servers filesystem.
When safe mode is enabled, PHP
checks whether the files or directories you are about to operate on have
the same UID (owner) as the script that is being executed. In addition,
you cannot set the SUID, SGID and sticky bits.
See also chown() and