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Tag: linux

Search and replace file content using shell script

I want to search and replace specific value in a file, here is the content of the file I want to replace DocumentRoot /var/www/html with DocumentRoot /var/www/html/centos I tried the following This is not working, can someone point me to the right direction. Thanks Answer The line you are trying to replace is…

Can resource attributes depend on file-presence?

I’m writing a module, that will provide for mirrored yum-repositories on our network. The single server will host the mirrors offering them to other hosts (and itself). I have a problem with the initial chicken-and-egg — the first download may not happen for a while, but, if I enable a new reposit…

Using the setuid bit in Linux

I have this C file: I compile it, set the UID and GID both to root and set the setuid bit, so that it looks like this: However when I call $ ./a.out I still get: What am I doing wrong? Answer The real user ID is still the user that called the program, but the effective user ID is

How to move window offscreen with wmctrl

I am trying to programmatically move a window so that it is partially on screen. For instance, clicking the VLC title bar and dragging it so that only half the window is visible works just fine. When I output the results of wmctrl -lG this works just fine: However, when I then move it back on screen and try a…

Print error for missing argument

I am trying to write a script which will check number of arguments for first and second number; if both variable entered, it will do the calculation; if one argument is missing, it will print error message. Here what I’ve done so far: I am always getting error message even though I enter both of the num…