Sep 17, 2012 · Meaning of "=~" operator in shell script [duplicate] Asked 13 years, 1 month ago Modified 12 years, 3 months ago Viewed 96k times

What does $# mean in shell? I have code such as if [ $# -eq 0 ] then I want to understand what $# means, but Google search is very bad for searching these kinds of things.

Oct 4, 2016 · I understand the basic difference between an interactive shell and a non-interactive shell. But what exactly differentiates a login shell from a non-login shell? Can you give …

When going through one shell script, I saw the term "$?". What is the significance of this term?

Sep 14, 2012 · $! is the PID of the most recent background command. $0 is the name of the shell or shell script. Most of the above can be found under Special Parameters in the Bash …

The shell is the program which actually processes commands and returns output. Most shells also manage foreground and background processes, command history and command line editing.

In man bash we can read in Shell Builtin Commands section (online doc): Unless otherwise noted, each builtin command documented in this section as accepting options preceded by - accepts …

Nov 15, 2010 · A bashism is a shell feature which is only supported in bash and certain other more advanced shells. It will not work under busybox sh or dash (which is /bin/sh on a lot of …

I am writing a shell script to run under the KornShell (ksh) on AIX. I would like to use the mkdir command to create a directory. But the directory may already exist, in which case I do not …

Feb 27, 2011 · There is a variation of running multiple commands in one line in the shell where you want them to run simultaneously rather than one after the other. The OP was interested in …