PHP's mkdir() function creates a safer permission setting method for folders, _PHP tutorial

php’s mkdir() function is a safer way to set permissions when creating a folder,

Problem description:
A directory is created using the following php code. The expected permission of the directory is 0777, and the actual result is 0755

Copy code The code is as follows:

mkdir('./aa/',0777);

Analysis and test results:

1. The directory permissions specified by the mkdir() function can only be less than or equal to the default permissions set by the system umask.

For example, the default umask of Linux is generally 0022, that is, the default permission to create a directory is 0755, so at this time php mkdir('./aa/',0777) gets the permission of the directory to be 0755.

Copy code The code is as follows:

xw@xw-X201:~/Desktop/dd/aa$ umask
0022
xw@xw-X201:~/Desktop/dd/aa$ php -r "mkdir('./xw/',0777);"
xw@xw-X201:~/Desktop/dd/aa$ php -r "mkdir('./xw1/',0755);"
xw@xw-X201:~/Desktop/dd/aa$ php -r "mkdir('./xw2/',0747);"
xw@xw-X201:~/Desktop/dd/aa$ ll
Total dosage 20
drwxrwxrwx 5 xw xw 4096 2012-06-01 11:58 ./
drwxr-xr-x 6 xw xw 4096 2012-06-01 11:26 ../
drwxr-xr-x 2 xw xw 4096 2012-06-01 11:57 xw/
drwxr-xr-x 2 xw xw 4096 2012-06-01 11:58 xw1/
drwxr--r-x 2 xw xw 4096 2012-06-01 11:58 xw2/

Change the system default permission to 777, mkdir() can specify greater permissions

Copy code The code is as follows:

xw@xw-X201:~/Desktop/dd/aa$ umask 000
xw@xw-X201:~/Desktop/dd/aa$ php -r "mkdir('./xw2/',0777);"
xw@xw-X201:~/Desktop/dd/aa$ ll
Total usage 12
drwxrwxrwx 3 xw xw 4096 2012-06-01 12:08 ./
drwxr-xr-x 6 xw xw 4096 2012-06-01 11:26 ../
drwxrwxrwx 2 xw xw 4096 2012-06-01 12:08 xw2/

2.chmod() function is not affected by the system umask and can set permissions greater than the system default permissions.

Copy code The code is as follows:

xw@xw-X201:~/Desktop/dd/aa$ umask
0022
xw@xw-X201:~/Desktop/dd/aa$ php -r "mkdir('./xw1/',0777);"
xw@xw-X201:~/Desktop/dd/aa$ php -r "mkdir('./xw2/');"
xw@xw-X201:~/Desktop/dd/aa$ php -r "mkdir('./xw3/');chmod('./xw3/',0777);"
xw@xw-X201:~/Desktop/dd/aa$ ll
Total dosage 20
drwxrwxrwx 5 xw xw 4096 2012-06-01 12:12 ./
drwxr-xr-x 6 xw xw 4096 2012-06-01 11:26 ../
drwxr-xr-x 2 xw xw 4096 2012-06-01 12:11 xw1/
drwxr-xr-x 2 xw xw 4096 2012-06-01 12:11 xw2/
drwxrwxrwx 2 xw xw 4096 2012-06-01 12:12 xw3/

3. The system’s mkdir command can set permissions greater than the default value.

Copy code The code is as follows:

xw@xw-X201:~/Desktop/dd/aa$ umask
0022
xw@xw-X201:~/Desktop/dd/aa$ mkdir -m0777 xw
xw@xw-X201:~/Desktop/dd/aa$ ll
Total usage 12
drwxrwxrwx 3 xw xw 4096 2012-06-01 12:18 ./
drwxr-xr-x 6 xw xw 4096 2012-06-01 11:26 ../
drwxrwxrwx 2 xw xw 4096 2012-06-01 12:18 xw/

​

Summary:

If php wants to create a directory with read and write permissions, it is best to use the following code. Do not directly use the mkdir function to specify permissions to avoid the impact of system umask

Copy code The code is as follows:

mkdir('./xw/');
chmod('./xw/',0777);

http://www.bkjia.com/PHPjc/851347.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/851347.htmlTechArticlephp’s mkdir() function creates a folder with a safer permission setting method. Problem description: Use the following php code to create A directory was created, and the expected directory permissions were 0777, but the actual result was 0755...