Added a section on functions in ULT; minor edits to SciTE section.
--- a/ult/Section_5.rst Thu Sep 17 23:58:10 2009 +0530
+++ b/ult/Section_5.rst Fri Sep 18 14:46:54 2009 +0530
@@ -607,6 +607,56 @@
echo "True"
done
+Functions
+---------
+
+When a group of commands are repeatedly being used within a script, it is convenient to group them as a function. This saves a lot of time and you can avoid retyping the code again and again. Also, it will help you maintain your code easily. Let's see how we can define a simple function, ``hello-world``. Functions can be defined in bash, either using the ``function`` built-in followed by the function name or just the function name followed by a pair of parentheses.
+::
+
+ function hello-world
+ {
+ echo "Hello, World.";
+ }
+
+ hello-world () {
+ echo "Hello, World.";
+ }
+
+ $ hello-world
+ Hello, World.
+
+Passing parameters to functions is similar to passing them to scripts.
+::
+
+ function hello-name
+ {
+ echo "Hello, $1.";
+ }
+
+ $ hello-name 9
+ Hello, 9.
+
+Any variables that you define within a function, will be added to the global namespace. If you wish to define variables that are restricted to the scope of the function, define a variable using the ``local`` built-in command of bash.
+
+We shall now write a function for the word frequency generating script that we had looked at in the previous session.
+
+::
+
+ function word_frequency {
+ if [ $# -ne 1 ]
+ then
+ echo "Usage: $0 file_name"
+ exit 1
+ else
+ if [ -f "$1" ]
+ then
+ grep "[A-Za-z]*" -o "$1" | tr 'A-Z' 'a-z' | sort | uniq -c | sort -nr | less
+ fi
+ fi
+ }
+
+As an exercise, modify the function to accept the input for the number of top frequency words to be shown (if none is given, assume 10).
+
Further Reading:
----------------
--- a/ult/session4.rst Thu Sep 17 23:58:10 2009 +0530
+++ b/ult/session4.rst Fri Sep 18 14:46:54 2009 +0530
@@ -428,7 +428,7 @@
SciTE
-----
-SciTE is a *source code* editor, that has a feel similar to the GUI text editors. It has a wide range of features that are extremely useful for a programmer, editing code. Also it aims to keep configuration simple, and the user needs to edit a text file to configure SciTE to his/her liking.
+SciTE is a *source code* editor, that has a feel similar to the commonly used GUI text editors. It has a wide range of features that are extremely useful for a programmer, editing code. Also it aims to keep configuration simple, and the user needs to edit a text file to configure SciTE to his/her liking.
Opening, Saving, Editing files with SciTE is extremely simple and trivial. Knowledge of using a text editor will suffice.