Visit Our UNIX and Linux User Community

Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

umask(2) [osf1 man page]

umask(2)							System Calls Manual							  umask(2)

NAME
umask - Sets and gets the value of the file creation mask SYNOPSIS
#include <sys/types.h> #include <sys/stat.h> mode_t umask ( mode_t cmask ); STANDARDS
Interfaces documented on this reference page conform to industry standards as follows: umask(): POSIX.1, XPG4, XPG4-UNIX Refer to the standards(5) reference page for more information about industry standards and associated tags. PARAMETERS
Specifies the value of the file mode creation mask. DESCRIPTION
The umask() function sets the file mode creation mask of the process to the value of the cmask parameter and returns the previous value of the mask. The cmask parameter is constructed by logically ORing file permission bits defined in the sys/mode.h header file. Whenever a file is created (by the open(), mkdir(), or mknod() function), all file permission bits set in the file mode creation mask are cleared in the mode of the created file. This clearing lets users restrict the default access to their files. The mask is inherited by child processes. RETURN VALUES
Upon successful completion, the previous value of the file mode creation mask is returned. RELATED INFORMATION
Commands: chmod(1), mkdir(1), Bourne shell sh(1b), POSIX shell sh(1p), umask(1) Functions: chmod(2), mkdir(2), mknod(2), open(2), stat(2) Standards: standards(5) delim off umask(2)

Check Out this Related Man Page

UMASK(2)						     Linux Programmer's Manual							  UMASK(2)

NAME
umask - set file mode creation mask SYNOPSIS
#include <sys/types.h> #include <sys/stat.h> mode_t umask(mode_t mask); DESCRIPTION
umask() sets the calling process's file mode creation mask (umask) to mask & 0777 (i.e., only the file permission bits of mask are used), and returns the previous value of the mask. The umask is used by open(2), mkdir(2), and other system calls that create files to modify the permissions placed on newly created files or directories. Specifically, permissions in the umask are turned off from the mode argument to open(2) and mkdir(2). The constants that should be used to specify mask are described under stat(2). The typical default value for the process umask is S_IWGRP | S_IWOTH (octal 022). In the usual case where the mode argument to open(2) is specified as: S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH (octal 0666) when creating a new file, the permissions on the resulting file will be: S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH (because 0666 & ~022 = 0644; i.e., rw-r--r--). RETURN VALUE
This system call always succeeds and the previous value of the mask is returned. CONFORMING TO
SVr4, 4.3BSD, POSIX.1-2001. NOTES
A child process created via fork(2) inherits its parent's umask. The umask is left unchanged by execve(2). The umask setting also affects the permissions assigned to POSIX IPC objects (mq_open(3), sem_open(3), shm_open(3)), FIFOs (mkfifo(3)), and UNIX domain sockets (unix(7)) created by the process. The umask does not affect the permissions assigned to System V IPC objects created by the process (using msgget(2), semget(2), shmget(2)). SEE ALSO
chmod(2), mkdir(2), open(2), stat(2), acl(5) COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. Linux 2008-01-09 UMASK(2)

15 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

umask with find

Hi, Will umask work with find command ? I was trying to do find /newdir/apps/ -type d -name 'par' -print -exec umask 117 {} \; it returns with find: umask: Permission denied , I've checked permission of all the directores, they have 770. however, If I use the command find... (4 Replies)
Discussion started by: braindrain
4 Replies

2. Linux

help on umask

hai guys , i am having problem in getting the knowledge about umask. actually when i am putting command as umask some value is coming like 0022 by defalut. we can change its value also. but the main thing is thye file permisiion actually depends upon umask.how is it depends upon umask i want to... (6 Replies)
Discussion started by: suvendu4urs
6 Replies

3. UNIX for Dummies Questions & Answers

Unmask

Hi All, I'm a newbie to UNIX I'm learning AIX 5l Basics I'm unable to execute UNMASK command as mentioned. Could any one help me. (6 Replies)
Discussion started by: udayakumar
6 Replies

4. UNIX for Advanced & Expert Users

file creation

Hi, Is there any way to restrict directories with one type of file creation. regards. (8 Replies)
Discussion started by: guguli
8 Replies

5. HP-UX

Problem With exceutable file creation

Hello , I came up with a new problem during creation of an exceutable file. My application all the c files and links them to create a new executable file. Till last month everything was fine and yester day i tried to change one file and tried to create an exe file but unsuccesfull. I am... (8 Replies)
Discussion started by: jagan_kalluri
8 Replies

6. Solaris

umask

Due to urgent requirement to resolve some permission issues , I wish to set solaris 8 server so that any file written is on 777 . I guess need to set umask , how to set it ?? (7 Replies)
Discussion started by: falcon16
7 Replies

7. UNIX for Advanced & Expert Users

umask

Hi, Please, let me know how the umask is working? As per my understanding is aprt from subtracting from 666/777, logical gate operation is performing. Ex: If I set uname 011, it gave the permission like 666 for file. Request you to explain which gate's operation performed. $uname 011... (4 Replies)
Discussion started by: Nagapandi
4 Replies

8. UNIX for Dummies Questions & Answers

Monitoring umask execution

Good Day! I would like to ask, is there a way to find out the list of users or scripts that executed a umask command for a given time? Our server has been having issues about files being written with 000 access, and we need to find out if it's because someone or some code is playing around with... (4 Replies)
Discussion started by: mike_s_6
4 Replies

9. UNIX for Dummies Questions & Answers

How to calculate umask values?

Hi, I was trying to understand how to calculate umask value but couldnt get the right way to calculate it. can some one please give me a small formula or easy method to do it? Thanks, Waseem (4 Replies)
Discussion started by: ahmedwaseem2000
4 Replies

10. UNIX for Dummies Questions & Answers

How to set default permission

Hey Guys, First post here. I just started learning UNIX a few weeks ago. My issue: I use FreeNAS which is based off of UNIX in my network environment which hosts files that my team needs to access. Each user has their own login but we are all part of a group called "ITLIC". I have a share... (15 Replies)
Discussion started by: uglycustoomer
15 Replies

11. Shell Programming and Scripting

umask and groups

Hi I see that I can use umask to set the default permissions on files created by a script like so - umask u=rwx,g=rwx,o= So that would grant rwx to the user and group. My question is how do I control the group this applies to? I want a script to create files under... (3 Replies)
Discussion started by: steadyonabix
3 Replies

12. Shell Programming and Scripting

How to change umask in shell scripting?

Hi, I have manually changed umak value by umask 0033 , After that i would like to change umask value into 0022 through shell scripting.. But it is changing while running the script. Once come out from script, it has not changed ... Ex: >umask 0033 >./1.sh 0022 >umask 0033 plz Any... (4 Replies)
Discussion started by: Mani_apr08
4 Replies

13. Red Hat

Changing system-wide for umask

Hi everybody, How can I change the default UMASK for non root users, e.g. I want the umask for every new created user will be 0044. Thanks (6 Replies)
Discussion started by: leo_ultra_leo
6 Replies

14. Shell Programming and Scripting

Cron and umask

Hi All, Please help to understand what I am missing. The default umask as in /etc/profile is 022. The Script running in Cron creates file with umask 026. The default User shell is ksh and the script runs on bash. How the Cron is creating the files with 026 umask, how to make it create files... (4 Replies)
Discussion started by: sathyaonnuix
4 Replies

15. Solaris

Umask permission

Hi All please help in this .. I have application user called: startsys umask already defined in the profile of application user as umask 033. Actually application creating files once the file getting create it created with different permission which is not the same of the defined... (8 Replies)
Discussion started by: AbuAliiiiiiiiii
8 Replies

Featured Tech Videos