Comparison of Features of three UNIX shells

FEATURE	C SHELL	BOURNE SHELL	KORN SHELL
Variables Assign values to variables	set x = 5	x=5	x=5
Accessing values of variables	echo $x	echo $x	echo $x or print $x
Command Substitution Assigning output of command	set d = `date`	d=`date`	d=$(date)
Accessing values	echo $d	echo $d	print $d
Arithmetic operations	@ var = 5 +1	var=`expr 5 + 1`	((var = 5 +1))
Aliases	alias m more	Not available	alias m=more
Programming Constructs: If C then	if (expr) then commands endif	if [ expr ] then commands fi	if (( expr )) then commands fi
If C then else	if ( expr) then commands else if commands else commands endif	if [ expr ] then commands elif commands else commands fi	if (( expr )) then commands elif commands else commands fi
Switch and case	switch (value) case pattern1: commands breaksw case pattern2: commands breaksw default: command breaksw endsw	case value in pattern1) commands ;; pattern2) commands;; *) commands ;; esac	case value in pattern1) commands;; pattern2) commands;; *) commands ;; esac
goto	goto label	Not Available	Not Available
if	if	Not Available	Not Available
Loops While	while (expr) commands end	while command do command done	while command do command done
For/foreach	foreach var (list) commands end	for var in list do commands done	for var in list do commands done
until	Not available	until command do command done	until command do command done
Initialization Files Executed at login	.login	.profile	.profile
Executed every time shell is invoked	.cshrc	Not available	.kshrc
Relational Operators Equal to Not equal to Less than or equal Less than Greater than or equal to Greater than And operator Or operator	== != <= < >= > && ||	= -ne -le -lt -ge -gt -a -o	= != <= < >= > && ||