Positional parameters set
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.