I want to replace $foo with bar. This works fine. But this command does not work fine when I use the -r option. Why doesn’t this work. Here is an example of what works with -r option. The real question is: Why does $ need to be escaped only while using the -r option. What would $ mean otherwise with
“Too many open files” – can’t remove a directory
I’ve created a large tree of empty directories in an Android emulator, around 1024. Now whenever I try to remove it with rm -rf 1/ I get a “Too many open files” error. How can I remove it? Answer Please try to use ulimit to set the open file handle as 4000 or more, you can use “ulimit …
What’s the intention of waitpid
The sample code below is from linux man page waitpid function. Can the last else if be replaced with else? When I write code, I would write like:if, else if, and end with else. So I think it is strange in the sample code. Answer Here’s the question I think you are asking: Is it possible for waitpid to r…
tickless kernel , isolcpus,nohz_full,and rcu_nocbs
I have add “isolcpus=3 nohz_full=3 rcu_nocbs=3” in grub.conf in RedHat 7.1 , kernel: linux 3.10.0-229 kernel and according to http://www.breakage.org/2013/11/15/nohz_fullgodmode/ I also execute the following command : The box has only 4 cpu cores , I run the following shell : look like work perfec…
Correct way to set a crontab to stop and start mysql and httpd
i’m trying to create a shell script to stop and start mysql and httpd every saturday on 3am, i’m doing it: myscript.sh: and setting the crontab to: It’s correct way to do it? i’m stopping and starting mysql and httpd cuz use of memory, should i do some check before stop them? or i can …
ssh + ssh is stuck on remote machine [closed]
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. This question does not appear to be about programming within the scope defined in the help center. Closed 6 years ago. Improve this question simple script in order to perform reboot on Linux machine after run…
How does elf-loader knows the address of stderr and stdout
I am disassembling a very simple ELF program (Linux x86). With IDA PRO software I see stdout and stderr in .bss-section. And I haven’t found anything that sets the values of stdout or stderr. How does it work? Сan stdout and stderr be null? Answer So you mean stdout and stderr should always be at the sa…
Re-write write-protected file
Every 4 hours files are updated with new information if needed – i.e. if any new information has been processed for that particular file (files correspond to people). I’m running this command to convert my .stp files (those being updated every 4 hours) to .xml files. My script is in Snakemake (pyt…
Not able to stop the tomcat server in linux
I am trying to stop the tomcat server through linux command. using the above command is giving following error message : I have started the server using ./catalina.sh stop command. Answer I found the way to kill the server, first I found its process Id using : ps -eaf | grep tomcat then killed the required pr…
is default port numbers are alwasy 4 digit [closed]
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. This question does not appear to be about a specific programming problem, a software algorithm, or software tools primarily used by programmers. If you believe the question would be on-topic on another Stack …