tcsh script if statement

Question

I need to loop through a bunch of different scenarios (variable scen), but can't figure out how to use the if statements in the tcsh shell script. Getting the error "if: Expression Syntax" Can someone please tell me what I have wrong? Simplified code follows! Thanks!

#!/bin/tcsh -f
#
set val = 0

foreach scen ( a b )

echo $scen

if ($scen==a) then
  echo $scen
else
  echo $val
endif
end

I tried adding square brackets in place of parenthesis on the foreach statement and got error "foreach: Words not parenthesized" — user50679, Nov 05 '13 at 21:17
Tried add square brackets in place of parenthesis on if statement and got error "[a==a]: No match." — user50679, Nov 05 '13 at 21:20

ntc2 · Accepted Answer · 2013-11-05T21:40:11.807

Solution to your problem

Apparently you need spaces around the equality comparison ==. This works:

#!/bin/tcsh -f
#
set val = 0

foreach scen ( a b )

echo $scen

if ($scen == a) then
  echo $scen
else
  echo $val
endif
end

producing:

a
a
b
0

Unsolicited advice

Also, unless you have to be using tcsh here, I suggest using a better shell like bash or zsh. Here are some arguments against csh and tcsh:

For comparison, here's your code in bash (and zsh):

#!/bin/bash

# No space around equal sign in assignment!
val=0

for scen in a b; do
  echo $scen

  if [[ $scen == a ]]; then
    echo $scen
  else
    echo $val
  fi
done

There's no important difference here, but see the above articles for examples where csh would be a bad choice.

tcsh script if statement

1 Answers1

Solution to your problem

Unsolicited advice

Linked