The following table is a sampling of features that are different among the three shells:
| Meaning/Action | bash | csh | tcsh |
|---|---|---|---|
| Default prompt. | $ |
% |
% |
| Force redirection. | >| | >! | >! |
| Force append. | >>! | >>! | |
| Variable assignment. | var=val | set var=val | set var=val |
| Set environment variable. | export var=val | setenv var val | setenv var val |
| Number of arguments. | $# | $#argv | $#argv |
| Exit status. | $? | $status | $? |
| Execute commands in file. | . file | source file | source file |
| End a loop statement. | done | end | end |
| End case or switch. | esac | endsw | endsw |
Loop through variables. |
for/do | foreach | foreach |
| Sample if statement. | if [ $i -eq 5 ] | if ($i==5) | if ($i==5) |
| End if statement. | fi | endif | endif |
| Set resource limits. | ulimit | limit | limit |
| Read from terminal. | read | $< | $< |
| Make a variable read-only. | readonly | set -r | |
File inquiry operator; tests for nonzero size. |
-s | ||
| Complete current word. | Tab | Tab | |
| Ignore interrupts. | trap 2 | onintr | onintr |
| Begin until loop. | until/do | until | until |
| Begin while loop. | while/do | while | while |
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