Difference between revisions of "Shell scripting tutorial"

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imported>ThorstenStaerk
imported>ThorstenStaerk
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   then \
 
   then \
 
     echo "I know you"
 
     echo "I know you"
 +
 +
= calling commands =
 +
Calling [[command]]s in a bash script is as easy as it can be: You just write the command to be called, like this:
 +
echo "Now calling a browser"
 +
firefox
 +
echo "Continuing with the script"
  
 
= See also =
 
= See also =

Revision as of 00:21, 2 January 2012

This is a tutorial for bash shell scripting.

Hello world

echo "hello world"
#!/bin/bash
echo "hello world"

input

echo "what is your name? "
read name
echo "hello $name"

Note that the variable is called $name, however the correct statement to read it is

read name

It is a common mistake to write

read $name

which means "read a string and store it into the variable whose name is stored in $name"

conditions

echo "what is your name? "
read name
if [ $name = "Thorsten" ]; then echo "I know you"

common mistakes

Common mistakes are:

line feeds

Let's look at the following script:

read name
if [ $name = "Thorsten" ]; then echo "I know you"

Instead of a semicolon you can write a line feed like this:

read name
if [ $name = "Thorsten" ]
  then echo "I know you"

And instead of a line feed you can use a semicolon:

read name; if [ $name = "Thorsten" ]; then echo "I know you"

If you want to insert a line feed where you do not need one, e.g. to make the code better readable, you must prepend it with a backslash:

read \
  name
if [ $name = "Thorsten" ]
  then \
    echo "I know you"

calling commands

Calling commands in a bash script is as easy as it can be: You just write the command to be called, like this:

echo "Now calling a browser"
firefox
echo "Continuing with the script"

See also