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Accepted
Jiew Meng
Asked: 2011-08-14 05:10:37 +0800 CST

.sh files requires `sh app.sh` even with `#!/bin/bash` line

  • 772

I am under the impression that if I include the line

#!/bin/bash

at the start of my file, it will be recognized as a bash script that I can run just by 

file.sh

instead of 

sh file.sh

But in my case, file.sh gives something like test.sh gives test.sh: command not found. Why is that?

UPDATE

I notice I need to use ./. But I thought it will look in the current directory anyway?

./test.sh
bash

2 Answers

  1. Best Answer

    First you need to make sure the file is executable:

    chmod +x file.sh

    And then to run it, you either need to put it in your PATH, i.e., one of the directories of files the OS searches when looking for files to run, which you can find with echo $PATH, or else you need to type in:

    ./file.sh

    Rather than just type file.sh.

    You can just type file.sh, if it's in your PATH, which I recommend. A good place is in ~/bin. Create that folder if it's not there, and under Ubuntu, it'll get added to your path when you log in.

    • 13

  2. You need to start it with ./file.sh, because the current dir is not in the PATH.

    If this isn't sufficient, becaused you missed, what frabjous suggests, to chmod a+x, you should start programs beginning with a shebang #!/bin/bash with 

    bash file.sh

    not

    sh file.sh

    even if sh is a symbolic link to /bin/bash.

    The shell checks how it was invoked, and can be invoked as sh to act in a compatible mode, therefore it can fail to handle some bashisms, which would work if invoked as bash file.sh.

    That was not your problem, but might become one, if you don't know these subtle distinction.

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