Common Features
The following table is a sampling of features that are common to bash, csh, and tcsh. Note that tcsh is an enhanced version of csh; therefore, tcsh includes all features of csh, plus some others.
Symbol/Command | Meaning/Action |
---|---|
>
| Redirect output. |
>>
| Append output to file. |
<
| Redirect input. |
<<
| ``Here'' document (redirect input). |
|
| Pipe output. |
&
| Run process in background. |
;
| Separate commands on same line. |
*
| Match any character(s) in filename. |
?
| Match single character in filename. |
!
n
| Repeat command number n. |
[ ]
| Match any characters enclosed. |
( )
| Execute in subshell. |
` `
| Substitute output of enclosed command. |
" "
| Partial quote (allows variable and command expansion). |
\
| Quote following character. |
$
var
| Use value for variable. |
$$
| Process ID. |
$0
| Command name. |
$
n
| nth argument (0<n≤9). |
$*
| All arguments. |
#
| Begin comment. |
bg
| Background execution. |
break
| Break from loop statements. |
cd
| Change directories. |
continue
| Resume a program loop. |
echo
| Display output. |
eval
| Evaluate arguments. |
exec
| Execute a new shell or other program. |
fg
| Foreground execution. |
jobs
| Show active jobs. |
kill
| Terminate running jobs. |
newgrp
| Change to a new group. |
shift
| Shift positional parameters. |
stop
| Suspend a background job. |
suspend
| Suspend a foreground job. |
umask
| Set or list permissions on files to be created. |
unset
| Erase variable or function definitions. |
wait
| Wait for a background job to finish. |
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