sh-bang


A bash script is just a text file with commands in it. Command like the ones we can give on the command line. It does not have to have any particular extension, but often people use the .sh extension. For example foobar.sh In order to be able to run it we need to make it executable chmod u+x foobar.sh or to make it exacutable for all the users on the system use chmod +x foobar.sh. To ensure the script always executes as a bash script, and not as the "current shell of the user" we need to add ad a sh-bang line.

#!/bin/bash


examples/script/hello_world.sh
echo Hello
echo World

$ ./examples/script/hello_world.sh 
Hello
World


examples/script/hello_world_more.sh
echo Hello World

$ ./examples/script/hello_world_more.sh 
Hello World


examples/script/hello_world_n.sh
echo -n Hello
echo World

$ ./examples/script/hello_world_n.sh 
HelloWorld


examples/script/hello_world_space.sh
echo -n "Hello "
echo World

$ ./examples/script/hello_world_space.sh 
Hello World