Difference between revisions of "Shell scripting tutorial"

From Linuxintro
imported>ThorstenStaerk
imported>ThorstenStaerk
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* [[shell]]
 
* [[shell]]
 
* [[scripting]]
 
* [[scripting]]
* [[bash Operators]]
+
* [[bash operators]]
 
* http://en.wikibooks.org/wiki/Bash_Shell_Scripting
 
* http://en.wikibooks.org/wiki/Bash_Shell_Scripting
 
* http://wiki.linuxquestions.org/wiki/Bash_tips
 
* http://wiki.linuxquestions.org/wiki/Bash_tips
 
* http://wiki.linuxquestions.org/wiki/Bash
 
* http://wiki.linuxquestions.org/wiki/Bash

Revision as of 00:14, 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"

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"

See also