Shell Command Library - Linux Unix

Definition of Shell Command. (Shell Command Glossary

• Built-in shell commands are part of a shell.
• Each shell (e.g., C Shell, Bourne Shell and Korn Shell) has a set of commands built into its program.
• Shell commands vary from one shell to another, but the commands within each shell stay the same across Linux / Unix distributions and variants.
• To find out the usage of a shell command in the currently active shell on your computer, you can use the man command.

Also Known As: Built-in Shell Command

Important Note: Shell commands may vary in syntax and usage from one type of shell to another. The shell command library here is provided as general references. Use the man command to see how a command is used in a particular shell.

C Shell Commands and What They Do

The C shell provides the following built-in commands:

#	Marks a command.
alias	Displays alias.
bg	Resumes job in the background.
break	Resumes execution after the loop.
breaksw	Breaks from a switch command; resumes after the endsw command.
case	Defines a label in a switch command.
cd	Changes directory.
chdir	Changes directory, same as cd.
continue	Continues a loop.
default	Specifies the default case in a switch.
dirs	Displays the directory stack.
echo	Writes arguments to the standard output of the shell.
eval	Evaluates a command.
exec	Executes the command in the current shell.
exit	Exits the shell.
fg	Brings a job in the foreground.
foreach	Specifies a looping control statement and execute a sequence of commands until reaching an end command.
glob	Writes arguments to the standard output of the shell, like the echo command, but without the new line.
goto	Continues execution after the specified label.
hashstat	Displays hash table statistics.
history	Displays the history list.
if	Executes a command if condition met.
jobs	Lists active jobs.

kill	Sends a signal to a process. term (terminate) is the default signal.
limit	Sets or list system resource limits.
login	Logs on.
logout	Logs out.
nice	Changes the priority of commands run in the shell.
nohup	Ignores the hangup signal.
notify	Notifies the user about changes in job status.
onintr	Tells the shell what to do on interrupt.
popd	Pops the top directory off the directory stack and changes to the new top directory.
pushd	Exchanges the top two elements of the directory stack.
rehash	Re-computes the hash table of the contents of the directories in the path shell variable.
repeat	Repeats the execution of a command.
set	Displays or set the value of a shell variable.
setenv	Sets environment variables.
shift	Shifts shell arguments.
source	Reads commands from a script.
stop	Stops a background job.
suspend	Stops the current shell.
switch	Starts a switch.
time	Displays the time used to execute commands.
umask	Shows or set file permissions.
unalias	Removes command alias.
unhash	Disables the internal hash table.
unlimit	Removes limitations on system Resource.
unset	Deletes shell variables.
unsetenv	Deletes environment variables.
wait	Waits for background jobs to complete.
while …end	Executes the commands between the while and matching end statements repeatedly.
@	Displays or set the values of all the shell variables.