cmdtest(1) blackbox testing of Unix command line tools


cmdtest [-cCOMMAND] [--command=COMMAND] [--config=FILE] [--dump-config] [--dump-setting-names] [--generate-manpage=TEMPLATE] [-h] [--help] [--help-all] [--list-config-files] [--version] [--no-default-configs] [--dump-memory-profile=METHOD] [-k] [--keep] [--no-keep] [--log=FILE] [--log-keep=N] [--log-level=LEVEL] [--log-max=SIZE] [--log-mode=MODE] [--memory-dump-interval=SECONDS] [--output=FILE] [-tTEST] [--test=TEST] [--timings] [--no-timings] [FILE]...


cmdtest black box tests Unix command line tools. Given some test scripts, their inputs, and expected outputs, it verifies that the command line produces the expected output. If not, it reports problems, and shows the differences.

Each test case foo consists of the following files:

a script to run the test (this is required)
the file fed to standard input
the expected output to the standard output
the expected output to the standard error
the expected exit code
a shell script to run before the test
a shell script to run after test

Usually, a single test is not enough. All tests are put into the same directory, and they may share some setup and teardown code:

a shell script to run once, before any tests
a shell script to run before each test
a shell script to run after each test
a shell script to run once, after all tests

cmdtest is given the name of the directory with all the tests, or several such directories, and it does the following:

• execute setup-once

• for each test case (unique prefix foo):

--- execute setup
--- execute foo.setup
--- execute the command, by running foo.script,
and redirecting standard input to come from foo.stdin, and capturing standard output and error and exit codes
--- execute foo.teardown
--- execute teardown
--- report result of test: does exit code match foo.exit,
standard output match foo.stdout, and standard error match foo.stderr?

• execute teardown-once

Except for foo.script, all of these files are optional. If a setup or teardown script is missing, it is simply not executed. If one of the standard input, output, or error files is missing, it is treated as if it were empty. If the exit code file is missing, it is treated as if it specified an exit code of zero.

The shell scripts may use the following environment variables:

a temporary directory where files may be created by the test
name of the current test (will be empty for setup-once and teardown-once)
directory from which cmdtest was launched


-c, --command=COMMAND
ignored for backwards compatibility
fill in manual page TEMPLATE
-h, --help
show this help message and exit
-k, --keep
keep temporary data on failure
opposite of --keep
write output to FILE, instead of standard output
-t, --test=TEST
run only TEST (can be given many times)
report how long each test takes
opposite of --timings
show program's version number and exit

Configuration files and settings

add FILE to config files
write out the entire current configuration
write out all names of settings and quit
show all options
list all possible config files
clear list of configuration files to read


write log entries to FILE (default is to not write log files at all); use "syslog" to log to system log, "stderr" to log to the standard error output, or "none" to disable logging
keep last N logs (10)
log at LEVEL, one of debug, info, warning, error, critical, fatal (default: debug)
rotate logs larger than SIZE, zero for never (default: 0)
set permissions of new log files to MODE (octal; default 0600)


make memory profiling dumps using METHOD, which is one of: none, simple, or meliae (default: simple)
make memory profiling dumps at least SECONDS apart


To test that the echo(1) command outputs the expected string, create a file called echo-tests/hello.script containing the following content:
echo hello, world

Also create the file echo-tests/hello.stdout containing:

hello, world

Then you can run the tests:

$ cmdtest echo-tests
test 1/1
1/1 tests OK, 0 failures

If you change the stdout file to be something else, cmdtest will report the differences:

$ cmdtest echo-tests
FAIL: hello: stdout diff:
--- echo-tests/hello.stdout     2011-09-11 19:14:47 +0100
+++ echo-tests/hello.stdout-actual      2011-09-11 19:14:49 +0100
@@ -1 +1 @@
-something else
+hello, world
test 1/1
0/1 tests OK, 1 failures

Furthermore, the echo-tests directory will contain the actual output files, and diffs from the expected files. If one of the actual output files is actually correct, you can actualy rename it to be the expected file. Actually, that's a very convenient way of creating the expected output files: you run the test, fixing things, until you've manually checked the actual output is correct, then you rename the file.