wget bash script with parameters

Question

I'm running a bash script using

wget -O - https://myserver/install/Setup.sh | bash

How can I pass a parameter to the above script so it runs? something like

wget -O - https://myserver/install/Setup.sh parameter1 | bash

Answer 1

The standard format for the bash (or sh or similar) command is bash scriptfilename arg1 arg2 .... If you leave off all the first argument (the name or path of the script to run), it reads the script from stdin. Unfortunately, there's no way to leave off the firs argument but pass the others. Fortunately, you can pass /dev/stdin as the first argument and get the same effect (at least on most unix systems):

wget -O - https://myserver/install/Setup.sh | bash /dev/stdin parameter1

If you're on a system that doesn't have /dev/stdin, you might have to look around for an alternative way to specify stdin explicitly (/dev/fd/0 or something like that).

Edit: Léa Gris suggestion of bash -s arg1 arg2 ... is probably a better way to do this.

Answer 2

You can also run your script with:

wget -qO - 'https://myserver/install/Setup.sh' | bash -s parameter1

See: man bash OPTIONS -s

   -s        If the -s option is present, or if no arguments remain
             after option processing, then commands are read from the
             standard input.  This option allows the positional
             parameters to be set when invoking an interactive shell or
             when reading input through a pipe.

or alternatively use the -c option.

bash -c "$(wget -qO - 'https://myserver/install/Setup.sh')" '' parameter1

the '' defines the parameter $0 to be empty string. In a normal file based script invocation, the parameter $0 contains the caller script name.

See: man bash OPTIONS -c

   -c        If the -c option is present, then commands are read from
             the first non-option argument command_string.  If there are
             arguments after the command_string, the first argument is
             assigned to $0 and any remaining arguments are assigned to
             the positional parameters.  The assignment to $0 sets the
             name of the shell, which is used in warning and error
             messages.