bash golf problem

threshold.sh

#!/bin/bash
# Input:
#     output this 6
#     do not output this 5
#     output this 7
#
# Output (and a non-zero exit code):
#     output this 6
#     output this 7

THRESHOLD=5

cat test_file |
  ruby -ne "puts \$_ if \$_.split(' ').last.to_i > \"${THRESHOLD}\".to_i" | \
  ruby -e 'out = STDIN.read; puts out; exit(1) if out.length > 0'

If even awk is too much of an external language, rev |cut|rev can get the last column.

$ cat test 
output this 6
do not output this 5
$ (xargs -L1 -I% bash -c '[ $(echo % | rev | cut -d\  -f 1 | rev) -gt $THRESHOLD ] && echo %' | grep . && exit 1 || exit 0 ) < test
output this 6
$ echo $?
1

Or if the character count is more important than readability:

(xargs -L1 -I% bash -c '[ $(echo %|rev|cut -d\  -f1|rev) -gt $THRESHOLD ]&&echo %'|grep .;exit $(($? != 0)))

How about:

cat test_file | grep -qv ' [1-5]$'
exit $(($?^1))

This assumes that the threshold can be expressed as a nice regexp.

nice ideas everyone. Inspired by floere, I found a nice way to replace the second ruby incantation in my script:

egrep ".+"

Will probably use awk to replace the first one.

Not the shortest ever, but all bash:

while read line
do
 val=`echo $line | grep -Eo '[0-9]+'`
 if [[ "$val" -gt "$THRESHOLD" ]]; then
   echo $line
   exit 1
 fi
done

added extra test data to negate early exit solutions.

Combined above solutions to this:

#!/bin/bash

THRESHOLD=5

! cat test_file | \
  awk "\$NF > $THRESHOLD { print }" | \ # $NF = last field
  egrep ".+"                            # Set exit code if no output,
                                        # negated by preliminary `!`

You can remove the cat and apply the awk line directly to the test_file - if we're still golfing.

awk "\$NF > $THRESHOLD { print }"  test_file

Beautiful! :D

(Whoops! Accidental +1, sorry!)

@telemachus , you dont need print statement, it is the default behaviour

awk -v t=$THRESHOLD '$NF > t' test_file

Untested , but i'm sure it work , and less readable but shorter:

awk '$NF>'$THRESHOLD test_file