After, I stat() a file, how can I read the various permissions flags from the st_mode variable which is of type mode_t? I would like to do something like:
but I know that is the wrong syntax. I would like to check the S_IROTH flag which determines if the file is world-readable. Man pages explain what the flags are; no necessarily how to access them. I'm not a C expert.
Hi folks.
I'm just starting to teach myself shell scripting and am having some trouble with an if statement. I am working with a directory where only one file will reside at a time and need to evaluate if this file is compressed to determine subsequent steps. I'm using echo for testing purposes.... (2 Replies)
Hi,
I found this strange behaviour while using one of the makefiles.
Here is the snippet of the unix.mak that is necessary for this context
SO = SvSocket.o SvStmt.o SvOdbcWrapper.o \
OdbcCallReader.o MgrCalls.o OdbcSvProxy.o \
OdbcSvApp.o... (4 Replies)
Dear colleagues,
One of my friend have a problem with c code. While compiling a c program it displays a message like
"array type has incomplete element type". Any body can provide a solution for it.
Jaganadh.G (1 Reply)
hello everybody!
I want to create a file with permissions for read, write, and execute to everybody using C, so I write this code:
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
int main(){
int fileDescriptor;
fileDescriptor =... (2 Replies)
hello everybody and a happy new year!
i am trying the client-server model...i have no problem with sockets etc...
especially for server:there is a father who is listening for TCP connections from clients,the later send commands which parent shares to his children.
then children execute... (1 Reply)
Hi there,
I need your help in understanding the below Solaris 10 ifconfig output;
athnetspns02>ifconfig -a
lo0: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL> mtu 8232 index 1
inet 127.0.0.1 netmask ff000000
e1000g0:... (2 Replies)
Hi,
I have a file with few values in it. I need script help to read file line by line and check:
1/if it's a file (with extension eg .java .css .jar etc )
or
2/if it's a file without extension and treat it as a directory and then check if the directory exists in working copy else create one... (6 Replies)
Discussion started by: iaav
6 Replies
LEARN ABOUT LINUX
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)COLOPHON
This page is part of release 3.27 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)