sh

Nearly everywhere I've read, including Google's bash scripting style guide mention to necessity of quoting command substitutions (except when specifically desired of course). I understand the when/where/why of quoting command substitutions during general use. For example: echo "$(cat <<< "* useless string *")" rather than echo $(...) However for variable assignments specifically, I have seen so many examples as such: variable="$(command)" Yet I have found no instances where variable=$(command) is not equivalent. variable="$(echo "*")" and variable=$(echo "*") both set the value to '*'. Can

I have a Java command-line application, and would like to create an Ant* build script that will create all the required batch/shell scripts to run the application successfully including all the classpath variables. I need it to do the following: Create a shell script file for Linux/Unix and a batch file for Windows/DOS Add all classpath dependencies (from Maven or simply use the build path in Eclipse) Add any necessary boilerplate sh/bat code to run (ENV variables, JAVA_HOME, etc.) I found only a partial answer here . But I haven't found anything that does this basic and trivial task that

There are two different syntaxes for command substitution, FOO=$(echo bar) and FOO=`echo bar` As far as I know, the first method is defined in Bash, while the second is defined in sh . Consider the following use of command substitution in an sh script. #!/bin/sh FOO=$(echo bar) Does that fall under the definition of bashism ? bashisms, i.e. features not defined by POSIX (won't work in dash, or general /bin/sh). It's the same thing. So no it's not a bashism nor related to bash only. Command Substitution Command substitution allows the output of a command to be substituted in place of the

Inspired by this question : What should an if statement do when the condition is a command substitution where the command produces no output? NOTE: The example is if $(true); then ... , not if true ; then ... For example, given: if $(true) ; then echo yes ; else echo no ; fi I would think that $(true) should be replaced by the output of the true command, which is nothing. It should then be equivalent to either this: if "" ; then echo yes ; else echo no ; fi which prints no because there is no command whose name is the empty string, or to this: if ; then echo yes ; else echo no ; fi which is a

I've a question on how to tell which shell the user is using. Suppose a script that if the user is using zsh, then put PATH to his .zshrc and if using bash should put in .bashrc. And set rvmrc accordingly. #!/usr/bin/env bash export PATH='/usr/local/bin:$PATH'" >> ~/.zshrc source ~/.zshrc I've tried the following but it does not work : ( if [[ $0 == "bash ]]; then export PATH='/usr/local/bin:$PATH'" >> ~/.bashrc elif [[ $0 == "zsh" ]]; then export PATH='/usr/local/bin:$PATH'" >> ~/.zshrc fi # ... more commands ... if [[ $0 == "bash ]]; then [[ -s '/Users/`whoami`/.rvm/scripts/rvm' ]] && source