Why printf prints 5 and echo prints 6 characters? Answer First sentence of entry for echo in the bash man page (emphasis mine): Output the args, separated by spaces, followed by a newline. First sentence of the man page entry for printf: Write the formatted arguments to the standard output under the control o…
Tag: linux
write(2)/read(2) atomicity between processes in linux
I have a case where there are two processes which act on the same file – one as a writer and one as a reader. The file is a one line text file and the writer re-writes the line in a loop. reader reads the line. The pseudo code looks like this: Writer Process Reader Process After a while of
How do I run a simple Go server as a daemon in Debian?
I recently wrote a simple server in Go: It works perfectly well if compiled and then executed by ./go_http_server &. The problem is that it doesn’t survive reboots. So after some reading, I attempted to daemonize it by placing a script in /etc/init.d: …then running update-rc.d go_http_server d…
android insmod init_module failed (required key not available)
can some one help me? I have run imsmod like this: but I got an error: I googled it a lot, but there is no a perfect answer. Thanks in advance. Answer I think this is because mmdev.ko module is signed. You can check if module is signed or not using command readelf -S mmdev.ko | grep module_sig If it
How to write a bash script which automate entering “docker container” and doing other things?
I want to implement an automatic bash script which enters a running docker container, and do some stuffs: Executing the script on terminal: The output shows only login the docker container, but won’t do other operations. Is there any method to automate entering docker container and doing other things? A…
How to run linux without any DesktopEnvironment?
I have Manjaro installed on my system and for the Desktop Environment I have XFCE4 and for login manager LXDM everything works fine but when I try to change some of the lxdm-config option I can’t login to my user, the problem came from that I disable that option to shown the select session panel and aft…
using tr to strip characters but keep line breaks
I am trying to format some text that was converted from UTF-16 to ASCII, the output looks like this: The only text I want out of that is: So there is a line break “n” at the end of each line and when I use It is stripping the new line as well so all the text ends up in
mmap: Cannot allocate memory
I have a C program that computes the page fault service time in C. For this program I have 2 large files (of less than 3GB each – almost the size of the RAM) I get the following compiler warnings: When I run it with the command I get the error What does the code do? We map both the
Unexpected EOF while looking for matching `”‘ shell script
I get when I try to run a shell script that I made, but I don’t see any misquotes on lines 36-38 SCRIPT: Answer Fix escaping of ‘: replace all ‘ by ”’.
CentOS Unix Cron order of execution when all set to same time
I have a series of cron jobs running at the command line calling the php interpreter all by the same user configured to run once a day Do these all execute at once or do the execute in the order of entry in some cron table, complete and move on to the next cron job? Answer And to answer your