Positional parameters set

From assela Pathirana
Jump to navigationJump to search
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
Green info.gif

The commands on this page can be tried out on Cygwin installed in a windows PC or on any UNIX computer.

Following is an example of positional parameters created by command line arguments being later replaced by others.

#!/bin/bash
#try calling this with several arguments
echo '$1=' $1
echo '$2=' $2
echo '$3=' $3
set `ls`
echo '$1=' $1
echo '$2=' $2
echo '$3=' $3

The first echo statements will print the command line arguments; but the second set will print the first three files in the current directory! The set command replace the positional parameters with the output of ls command.