The test within the if statement does not catch nulls

Question

I have tested it with double braces for the "&&" and have tried it against "" for null values however every time it does not move down to the else statement.

#!/bin/bash
#find | grep
#find -a {} | grep {search}
function fg { 
        if [ -z $1 ] && [ -z $2 ]; then
        echo "Help: find {path} | grep {search} "

        else
        find $1 | grep $2

        fi 
}

fg

Yes, I have tried every variation I can think of I've assigned the arguments to variables and applied them in the if statement. — Hobnob
– Hobnob, Commented Jul 14, 2017 at 8:24

2 revs · Accepted Answer · 2017-07-13 13:31:08Z

1

Always quote your parameter expansions.

fg () { 
  if [ -z "$1" ] && [ -z "$2" ]; then
    echo "Help: must specify path and regular expression"
  else
    find "$1" -regex "$2"
  fi
}

fg

A cleaner way to check for unset or empty parameters, though, is via the :? operator.

fg () {
    : ${1:?Missing path}
    : ${2:?Missing regex}
    find "$1" -regex "$2"
}

edited Jul 13, 2017 at 13:31

community wiki

2 revs
chepner

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2 Comments

Hobnob Over a year ago

I couldn't use the top block of code but tried the bottom one and hasnt flagged any errors, however I cant verify that it works for me as I'm getting an unexpected token for the closing brace on the function.

Hobnob Over a year ago

Sorry for the late reply, tried the second block of code and still didn't work?

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