| Character |
Where |
Meaning |
| ESC |
csh |
Filename completion. |
| RETURN |
csh, sh |
Execute command. |
| space |
csh, sh |
Argument separator. |
| TAB |
csh, sh |
Argument separator. |
| TAB |
bash |
Filename completion. |
| # |
csh, sh |
Start a comment. |
| ` |
csh, sh |
Command substitution (backquotes). |
| " |
csh, sh |
Weak quotes. |
| ' |
csh, sh |
Strong quotes. |
| \ |
csh, sh |
Single?character quote. |
| $var |
csh, sh |
Variable. |
| ${var} |
csh, sh |
Same as $var. |
| $var:mod |
csh |
Edit var with modifier mod |
| ${var?default} |
sh |
If var not set, use default. |
| ${var=default} |
sh |
If var not set, set it to default and use that value. |
| ${var+instead} |
sh |
If var set, use instead. Otherwise, null string. |
| ${var?message} |
sh |
If var not set, print message (else default). If var set, use its value. |
| ${var#pat} |
ksh, bash |
Value of var with smallest pat deleted from start. |
| ${var##pat} |
ksh, bash |
Value of var with largest pat deleted from start. |
| ${var%pat} |
ksh, bash |
Value of var with smallest pat deleted from end. |
| ${var%%pat} |
ksh, bash |
Value of var with largest pat deleted from end. |
| | |
csh, sh |
Pipe standard output. |
| |& |
csh |
Pipe standard output and standard error. |
| ^ |
sh |
Pipe character (obsolete). |
| ^ |
csh, bash |
Edit previous command line. |
| & |
csh, sh |
Run program in background. |
| ? |
csh, sh |
Match one character. |
| * |
csh, sh |
Match zero or more characters. |
| ; |
csh, sh |
Command separator. |
| ;; |
sh |
[/td]End of case statement.[/tr]
|
| ~ |
csh, ksh, bash |
Home directory. |
| ~user |
csh, ksh, bash |
Home directory of user. |
| ! |
csh, bash |
Command history. |
| - |
Programs |
Start of optional argument. |
| - |
Programs |
Read standard input. (Only certain programs.) |
| $# |
csh, sh |
Number of arguments to script. |
| "$@" |
sh |
Original arguments to script. |
| $* |
csh, sh |
Arguments to script. |
| $- |
sh |
Flags set in shell. |
| $? |
sh |
Status of previous command. |
| $$ |
csh, sh |
Process identification number. |
| $! |
sh |
Process identification number of last background job. |
| $< |
csh |
Read input from terminal. |
| cmd1 && cmd2 |
csh, sh |
Execute cmd2 if cmd1 succeeds. |
| cmd1 || cmd2 |
csh, sh |
Execute cmd2 if cmd1 succeeds. |
| $(..) |
ksh, bash |
Command substitution. |
| ((..)) |
ksh, bash |
Arithmetic evaluation. |
| \. file |
sh |
Execute commands from file in this shell. |
| : |
sh |
Evaluate arguments, return true. |
| : |
sh |
Separate values in paths. |
| : |
csh |
Variable modifier. |
| [] |
csh, sh |
Match range of characters. |
| [] |
sh |
Test. |
| %job |
csh, ksh, bash |
Identify job number. |
| (cmd;cmd) |
csh, sh |
Run cmd;cmd in a subshell. |
| {} |
csh, bash |
In?line expansions. |
| {cmd;cmd;} |
sh |
Like (cmd;cmd) without a subshell. |
| >file |
csh, sh |
Redirect standard output. |
| >>file |
csh, sh |
Append standard output. |
| csh, sh |
Redirect standard input. | |
<
| csh, sh |
Read until word, do command and variable substitution. | |
| <<\word |
csh, sh |
Read until word, no substitution. |
|
| sh |
Read until word, ignoring leading TABs. |
| >>! file |
csh, sh |
Append to file, even if noclobber set and file doesn't exist. |
| >! file |
csh |
Output to file, even if noclobber set and file exists. |
| >| file |
ksh, bash |
Output to file, even if noclobber set and file exists. |
| >& file |
csh |
Redirect standard output and standard error to file. |
| m> file |
sh |
Redirect output file descriptor m to file. |
| m>> file |
sh |
Append output file descriptor m to file. |
| m< file |
sh |
Redirect input file descriptor m from file. |
| <&m |
sh |
Take standard input from file descriptor m. |
| <&? |
sh |
Close standard input. |
| >&m |
sh |
Use file descriptor m as standard output. |
| >&- |
sh |
Close standard output. |
| m<&n |
sh |
Connect input file descriptor n to file descriptor m. |
| m<&- |
sh |
Close input file descriptor m. |
| n>&m |
sh |
Connect output file descriptor n to file descriptor m. |
| m>&- |
sh |
Close output file descriptor m. |
