[Webinar] Streamline your web hosting managementRegister Today

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 344
  • Last Modified:

Grep Not Working After Changing Variable

From the command line, cat test | grep 'hello' works. But not when I change it within my script. Basically, trying to resolve an issue is user does a grep without using the ' (needed for multiple search).

I'm trying to manipulate grep so that this command would work: bash run hello:new

#!/bin/bash

if [ -n "$1" ]
then
  string=`echo "'${1/:/\\|}'"`;
  echo $string;
  cat test | grep $string;
fi

Open in new window

0
Neapolitan23
Asked:
Neapolitan23
  • 2
  • 2
2 Solutions
 
ozoCommented:
Try
string=${1/:/\\|}
0
 
simon3270Commented:
I don't think you need either the single quotes or the backslashes.  I just replaced the middle section with:
    string=${1//:/|}
    echo $string
    cat test | egrep "$string"

Open in new window

Note the "//" after the 1 in the first line - this replaces all colons with vertical bars, not just the first one (if there is more than one).  Also the "egrep" (or "grep -E" if you prefer), which is needed to search for these multiple strings.
0
 
ozoCommented:
Also,
 cat test |
is a Useless Use Of Cat when you can do
 grep $string < test
or
 grep $string  test


Even easier, you might
egrep $1
and call the script with  'peter|chris' instead of peter:chris
0
 
Neapolitan23Author Commented:
Dude, you are amazing. Thanks!
0
 
Neapolitan23Author Commented:
ozo: Your solution worked. And it works for multiple search even with regular grep.
simon3270: Your solution worked as well. The added value here was adding the extra / so that it can support multiple replace of :.

Very cool. And thanks to you both!
0

Featured Post

The 14th Annual Expert Award Winners

The results are in! Meet the top members of our 2017 Expert Awards. Congratulations to all who qualified!

  • 2
  • 2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now