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bashfor-loopsudo

Using sudo with for loop

I want to run a simple for loop command with sudo, but it isn't working:

sudo -i -u user for i in /dir; do echo $i; done

I get the following error:

-bash: syntax error near unexpected token `do'

Probably a very simple thing I am overlooking. Any help?

Solution

  • sudo wants a program (+arguments) as a parameter, not a piece of shell script. You can do this, though:

    sudo -i -u user sh -c 'for i in /dir; do echo $i; done'

    Note the single quotes. If you used double quotes, your shell would try to expand the $i before sudo (or, rather, the shell run by it) ever sees it.

    PS. a separate problem, as pointed out in a comment (only six years later), is that if you want to iterate over the files in a directory, the proper syntax is for i in /dir/*. for accepts a list, and /dir is a list... with one item. /dir/* expands to a list of files in /dir due to wildcard expansion.