Editing Shell script (section)

===Programming===
Many modern shells also supply various features usually found only in more sophisticated [[general-purpose programming language]]s, such as control-flow constructs, variables, [[Comment (computer programming)|comments]], arrays, [[subroutine]]s and so on. With these sorts of features available, it is possible to write reasonably sophisticated applications as shell scripts. However, they are still limited by the fact that most shell languages have little or no support for data typing systems, classes, threading, complex math, and other common full language features, and are also generally much slower than compiled code or interpreted languages written with speed as a performance goal.

The standard Unix tools [[sed]] and [[awk]] provide extra capabilities for shell programming; [[Perl]] can also be embedded in shell scripts as can other scripting languages like [[Tcl]]. Perl and Tcl come with graphics toolkits as well.