Table of Contents
List of Examples
Bash completion extends bashs standard completion behavior to achieve +
Table of Contents
List of Examples
Bash completion extends bashs standard completion behavior to achieve complex command lines with just a few keystrokes. This project was conceived to produce programmable completion routines for the most common Linux/UNIX commands, reducing the amount of typing sysadmins @@ -33,7 +33,7 @@ and programmers need to do on a daily basis.
Table of Contents
This document attempts to explain the basic styles and patterns that are used in the bash completion. New code should try to conform to these standards so that it is as easy to maintain as existing code. Of course every rule has an exception, but it’s important to know the rules nonetheless!
This is particularly directed at people new to the bash completion codebase, who are in the process of getting their code reviewed. Before getting a review, please read over this document and make sure your code conforms to the recommendations here.
Table of Contents
The bash-completion package contains an automated test suite. Running the tests should help verifying that bash-completion works as expected. The tests are also very helpful in uncovering software regressions at an early stage.
The bash-completion test suite is written on top of the DejaGnu testing framework. DejaGnu is written in Expect, which in turn uses Tcl — Tool command language.
Table of Contents
Installing DejaGnu should be easy using your local package manager.
Table of Contents
Table of Contents
This document attempts to explain the basic styles and patterns that are used in the bash completion. New code should try to conform to these standards so that it is as easy to maintain as existing code. Of course every rule has an exception, but it’s important to know the rules nonetheless!
This is particularly directed at people new to the bash completion codebase, who are in the process of getting their code reviewed. Before getting a review, please read over this document and make sure your code conforms to the recommendations here.
Table of Contents
The bash-completion package contains an automated test suite. Running the tests should help verifying that bash-completion works as expected. The tests are also very helpful in uncovering software regressions at an early stage.
The bash-completion test suite is written on top of the DejaGnu testing framework. DejaGnu is written in Expect, which in turn uses Tcl — Tool command language.
Table of Contents
Installing dependencies should be easy using your local package manager.
On Debian/Ubuntu you can use apt-get:
sudo apt-get install dejagnu tcllib
This should also install the necessary expect and tcl packages.
Table of Contents
The tests are grouped into different areas, called tool in DejaGnu:
Each tool has a slightly different way of loading the test fixtures, see Test context below.
The tests are run by calling runtest in the test directory:
runtest --outdir log --tool completion +
Each tool has a slightly different way of loading the test fixtures, see Test context below.
Table of Contents
The tests are run by calling runtest in the test directory:
runtest --outdir log --tool completion runtest --outdir log --tool install runtest --outdir log --tool unit
The commands above are already wrapped up in shell scripts within the test directory:
./runCompletion ./runInstall -./runUnit
Let’s consider this real-life example where an ssh completion bug is fixed. First you’re triggered by unsuccessful tests:
$ ./runCompletion +./runUnit
The test suite requires a connected terminal (tty). When invoked via cron, no tty is connected and the test suite may respond with this error:
can't read "multipass_name": no such variable
To run the tests successfully via cron, connect a terminal by redirecting stdin from a tty, e.g. /dev/tty50:
./runUnit < /dev/tty50
If the process doesn’t run as root, root will have to change the owner and +permissions of the tty.
In Linux, you can press alt-Fx or ctrl-alt-Fx to switch the console from +/dev/tty1 to tty7. There are many more /dev/tty* which are not accessed via +function keys. To be safe, use a tty greater than tty7?
Let’s consider this real-life example where an ssh completion bug is fixed. First you’re triggered by unsuccessful tests:
$ ./runCompletion
...
=== completion Summary ===
@@ -78,7 +81,7 @@ expect: does "ssh -F fixtures/ssh/config ls\r\nls lsattr lsb_rel
...
=== completion Summary ===
-# of expected passes 2Now let’s consider a unit test failure. First you’re triggered by unsuccessful tests:
$ ./runUnit +# of expected passes 2
Now let’s consider a unit test failure. First you’re triggered by unsuccessful tests:
$ ./runUnit
...
=== unit Summary ===
@@ -90,9 +93,9 @@ FAIL: Environment should stay cleanIn this case it appears Now, if we haven’t already figured out the problem, we can have a detailed look in From there, search up for the first line saying: This tells you where the actual output differs from the expected output. In this case it looks like the the function dbg.log to find out what’s going wrong. Open dbg.log and search for UNRESOLVED (or FAIL if that’s what you’re looking for):FAIL: Environment should stay clean
expect: does "..." match regular expression "..."
_known_hosts_real is unexpectedly modifying global variables cur and flag. In case you need to modify the test:$ vi lib/unit/_known_hosts_real.exp
The primary Wikipedia page is called +# of unexpected failures 1
Now, if we haven’t already figured out the problem, we can have a detailed look in dbg.log to find out what’s going wrong. Open dbg.log and search for UNRESOLVED (or FAIL if that’s what you’re looking for):
FAIL: Environment should stay clean
From there, search up for the first line saying:
expect: does "..." match regular expression "..."
This tells you where the actual output differs from the expected output. In this case it looks like the the function _known_hosts_real is unexpectedly modifying global variables cur and flag. In case you need to modify the test:
$ vi lib/unit/_known_hosts_real.exp
The primary Wikipedia page is called test suite and not testsuite, so that’s what this -document sticks to.
The name and location of this code generation script come from Ruby on Rails' script/generate.
Table of Contents
The test environment needs to be put to fixed states when testing. For instance the bash prompt (PS1) is set to the current test directory, followed by an ampersand (@). The default settings for bash reside in config/bashrc and config/inputrc.
For each tool (completion, install, unit) a slightly different context is in effect.
When the completions are tested, invoking DejaGnu will result in a call to completion_start() which in turn will start bash --rcfile config/bashrc.
Example 9.1. What happens when completion tests are run?
| runtest --tool completion +document sticks to.
The name and location of this code generation script come from Ruby on Rails' script/generate.
Table of Contents
The test environment needs to be put to fixed states when testing. For instance the bash prompt (PS1) is set to the current test directory, followed by an ampersand (@). The default settings for bash reside in config/bashrc and config/inputrc.
For each tool (completion, install, unit) a slightly different context is in effect.
When the completions are tested, invoking DejaGnu will result in a call to completion_start() which in turn will start bash --rcfile config/bashrc.
Example 10.1. What happens when completion tests are run?
| runtest --tool completion
V
+----------+-----------+
| lib/completion.exp |
@@ -117,7 +120,7 @@ document sticks to.Setting up bash once within completion_start() has the speed advantage that bash - and bash-completion - need only initialize once when testing multiple completions, e.g.:
runtest --tool completion alias.exp cd.exp
Example 9.2. What happens when install tests are run?
| runtest --tool install + +----------------------+
Setting up bash once within completion_start() has the speed advantage that bash - and bash-completion - need only initialize once when testing multiple completions, e.g.:
runtest --tool completion alias.exp cd.exp
Example 10.2. What happens when install tests are run?
| runtest --tool install
V
+----+----+
| DejaGnu |
@@ -131,7 +134,7 @@ document sticks to.Example 9.3. What happens when unit tests are run?
| runtest --tool unit + +-------------------------+
This is the bash configuration file (bashrc) used for testing:
# bashrc file for DejaGnu testsuite
# Use emacs key bindings
set -o emacs
@@ -171,10 +171,15 @@ unset -v \
COMP_TAR_INTERNAL_PATHS
# Load bash testsuite helper functions
-. lib/library.shThis is the readline configuration file (inputrc) used for testing:
# -*- mode: shell-script; sh-basic-offset: 8; indent-tabs-mode: t -*- -# ex: ts=8 sw=8 noet filetype=sh -# -# Readline init file for DejaGnu testsuite +. lib/library.sh + +# Local variables: +# mode: shell-script +# sh-basic-offset: 8 +# sh-indent-comment: t +# indent-tabs-mode: t +# End: +# ex: ts=8 sw=8 noet filetype=sh
This is the readline configuration file (inputrc) used for testing:
# Readline init file for DejaGnu testsuite
# See: info readline
# Press TAB once (instead of twice) to auto-complete
@@ -186,4 +191,12 @@ set completion-query-items -1
# Display completions sorted horizontally, not vertically
set print-completions-horizontally on
# Don't use pager when showing completions
-set page-completions off