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I can't figure out what the sh command is?

http://unixhelp.ed.ac.uk/CGI/man-cgi?sh

Does it execute a file?

like in tomcat:

sh /usr/local/tomcat/bin/shutdown.sh

Sorry, just confused.

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    @Chopper3: tags aren't for expressing your opinion, comments are. Jan 18, 2010 at 18:56
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    "In Ubuntu 6.10, the default system shell, /bin/sh, was changed to dash (the Debian Almquist Shell); previously it had been bash (the GNU Bourne-Again Shell)."—wiki.ubuntu.com/DashAsBinSh . dash is a little quicker than bash
    – noobninja
    Jan 11, 2020 at 20:51

2 Answers 2

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sh is the bourne shell.

There are several shells, of which bourne is the old standard, installed on all unix systems, and generally the one you can guarantee will exist.

The shell is the command interpreter that takes your input, provides output back to the screen, to the correct files, etc, and provides all the basic built-in commands you need to manage jobs, kill, test expressions, etc.

Your command above is saying to run that shell-script using the bourne shell. Different shells use different syntax, so using the correct shell is a requirement. The first line of the shell should also define which to use: #!/bin/sh says use /bin/sh

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    On many systems (like in Mac OS X), nowadays sh is actually bash, aka the Bourne-again shell. The command sh --version will tell one more. It's backwards compatible with the Bourne shell though.
    – Arjan
    Jan 19, 2010 at 6:32
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sh is the bourne shell. /usr/local/tomcat/bin/shutdown.sh is a shell script. sh file runs file as a shell script. generally one would just set the execute bit and run ./file.

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  • ok so I am going out and changing my shell implicitly to run that command, ok thanks.
    – user3183
    Jan 18, 2010 at 18:23
  • Techinically, you would be changing the script. Make sure the first line is: #!/bin/bash then: chmod +x /usr/local/tomcat/bin/shutdown.sh to make it executable
    – Alex
    Jan 18, 2010 at 18:28

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