C Shell
C Shell is an implementation of UNIX Shell.
Other implementations of UNIX Shell.
csh was the shell that William Joy wrote for BSD. csh accepted the same Unix commands as other shells, but had a very different syntax (for variable assignments, control flow, and such). csh is not compatible with the Bourne Shell.
BSD keeps the C shell at /bin/csh, but few persons use it.
Hashbang lines for C shell scripts should use the -f option:
<lang csh>#!/bin/csh -f</lang>
Syntax
| C | C Shell | Bourne Shell |
|---|---|---|
| <lang c>#include <stdio.h>
int main() { int n; n = 13;
printf("%d\n", n);
while (n != 1) {
if (n % 2)
n = 3 * n + 1;
else
n /= 2;
printf("%d\n", n);
}
return 0; }</lang> |
<lang csh>
if ($n % 2) then @ n = 3 * $n + 1 else @ n /= 2 endif echo $n end
|
<lang bash>
if expr $n % 2 >/dev/null; then n=`expr 3 \* $n + 1` else n=`expr $n / 2` fi echo $n done
|
<lang csh>% @ n = 10 - 3 - 2 % echo $n 9</lang>
<lang csh>% @ n = (10 - 3) - 2 % echo $n 9</lang>