I have created symbolic links to several frequently used commands, for example:
"lt" is a link to "ls -ltrgo|tail". What can I do to make these links available system-wide, or at least in the directories my coworkers are in most of the time? I have copied the link to several directories, and... (6 Replies)
Hi, I have a task to search for a file called 'Xstartup' in the whole system because there might be different versions of it which overrite eachother.
Can anyone suggest a smart command to run this search ? The machine needs to scan every single folder beginning from root.
Please help, I am... (5 Replies)
Hello,
I am new to shell scripting and I was trying to write a script that would force a system wide password change except for admins. I am having some trouble and any help that someone could give me would be greatly appreciated. I am trying to do it by using the UID as the marker for anyone... (6 Replies)
Hi all,
Is there any system wide limit on number of user threads. I only find nkthread as a tunable parameter,apart from the `per process limit`. (1 Reply)
Hi,
I need to look for a config file (ldap.conf) and pick the latest modified file.
`locate` tells me there are many ldap.conf's, some in /etc, /usr, /home, etc.
Is there some way I can sort them by last modified time via bash?
I was thinking maybe I could pipe the output of `locate` to `ls... (4 Replies)
Dear Fellows;
As being new to linux, i have tried to synamically load a custom library which overrides some system calls like conncet(), socket() etc.... for custom purposes.
It works well, if declaring the environment path LD_PRELOAD and execution of the application to be override... (0 Replies)
We need to have many of our users all send encrypted files to a single FTP server. The problem, if I understand how encryption/decryption works (which I don't), is that each user would normally have their own private and public key. The other end needs to be able to decrypt the file(s) using a... (6 Replies)
When looking for wherever a program or a filename appears in the system, a short scrip is "findinner" which another script calls with a long parameter list consisting of path names ending with ".sh" or ".menu". "findinner" looks like this:
# If not .savenn file, show name and result of grep.
#... (4 Replies)
I have downloaded and installed a library called htslib for specific bioinformatic use but not for the system (I'm using Ubuntu 18.04). Only parts of the library is needed for my exercise to parse data in a type called VCF format (basically tab-delimited file but contains many information in... (14 Replies)
Discussion started by: yifangt
14 Replies
LEARN ABOUT CENTOS
umask
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)