What is POSIX? I have read the Wikipedia article and I read it every time I encounter the term. The fact is that I never really understood what it is. Can anyone please explain it to me by explaining “the need for POSIX” too? 15 s 15 The most important things POSIX 7 defines C … Read more
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it’s on-topic for Stack Overflow. Closed 1 year ago. Improve this question On Linux, how can I add a directory to the $PATH so it remains persistent across different sessions? Background … Read more
Is it possible to use ls in Unix to list the total size of a sub-directory and all its contents as opposed to the usual 4K that (I assume) is just the directory file itself? total 12K drwxrwxr-x 6 *** *** 4.0K 2009-06-19 10:10 branches drwxrwxr-x 13 *** *** 4.0K 2009-06-19 10:52 tags drwxrwxr-x 16 … Read more
I tried to close the tomcat using ./shutdown.sh from tomcat /bin directory. But found that the server was not closed properly. And thus I was unable to restartMy tomcat is running on port 8080. I want to kill the tomcat process running on 8080. I first want to have the list of processes running on … Read more
I set a passphrase when creating a new SSH key on my laptop. But, as I realise now, this is quite painful when you are trying to commit (Git and SVN) to a remote location over SSH many times in an hour. One way I can think of is, delete my SSH keys and create … Read more
I just installed node and npm through the package on nodejs.org, and whenever I try to search or install something with npm, it throws the following error unless I sudo the command. I have a feeling this is a permissions issue? I am already the admin. npm ERR! Error: EACCES, open ‘/Users/chietala/.npm/-/all/.cache.json’ npm ERR! { … Read more
When writing shell programs, we often use /bin/sh and /bin/bash. I usually use bash, but I don’t know what’s the difference between them. What’s main difference between Bash and sh? What do we need to be aware of when programming in Bash and sh? 12 What is sh? sh (or the Shell Command Language) is … Read more
I assume everyone here is familiar with the adage that all text files should end with a newline. I’ve known of this “rule” for years but I’ve always wondered — why? Best Answer Because that’s how the POSIX standard defines a line: 3.206 Line A sequence of zero or more non- <newline> characters plus a … Read more
How do I iterate through each line of a text file with Bash? With this script: echo “Start!” for p in (peptides.txt) do echo “${p}” done I get this output on the screen: Start! ./runPep.sh: line 3: syntax error near unexpected token `(‘ ./runPep.sh: line 3: `for p in (peptides.txt)’ (Later I want to do … Read more
How do I recursively grep all directories and subdirectories? find . | xargs grep “texthere” * 2 26 grep -r “texthere” . The first parameter represents the regular expression to search for, while the second one represents the directory that should be searched. In this case, . means the current directory. Note: This works for … Read more
