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nutthick 05-24-2006 06:17 AM
bash search for a pattern within a string variable
 
Does anyone know a bash command to check for a pattern match within a string. For example, if I have a string "1 2 3 4 5". I need a function that would return true if I searched for "2 3", but false if I searched for "8 9".

Thanks

PS I tried searching this forum, but the search kept locking up, so sorry if this has been answered already.

druuna 05-24-2006 10:14 AM
Hi,

I don't know any bash internal that can do this, but the following code snippet is one way of solving this (there are probably a lot more):
Code:
#!/bin/bash

thisString="1 2 3 4 5"

searchString="8 9"

if `echo ${thisString} | grep "${searchString}" 1>/dev/null 2>&1`
then
  echo "True"
else
  echo "False"
fi
Hope this helps.

spirit receiver 05-24-2006 12:51 PM
There are built-in tests for extended regular expressions (similar to what druuna uses) or Bash patterns:
Code:
#! /bin/bash

VARIABLE="Let's test this string!"

# This is for regular expressions:
if [[ "$VARIABLE" =~ "Let's.*ring" ]]
then
    echo "matched"
else
    echo "nope"
fi

# And here we have Bash Patterns:
if [[ "$VARIABLE" == L*ing! ]]
then
    echo "matched"
else
    echo "nope"
fi

nutthick 05-31-2006 01:27 AM
Thanks I've got it working now

Columbo2 07-06-2008 10:32 PM
Needs tweaking
 
It works more like this:

Code:
kovacsbv@leviticus:~$ cat tmp.sh
#! /bin/bash

VARIABLE="Let's test this string!"

# This is for regular expressions:
if [[ "$VARIABLE" =~ "Let's.*ring" ]]
then
    echo "#1 matched"
else
    echo "#1 nope"
fi

if [[ "$VARIABLE" =~ Let\'s.*ring ]]
then
    echo "#2 matched"
else
    echo "#2 nope"
fi
kovacsbv@leviticus:~$ ./tmp.sh
#1 nope
#2 matched
kovacsbv@leviticus:~$

simon.sweetman 02-16-2011 05:16 PM
To get #1 matching remove quotes around RE or set compat31

Code:
shopt -s compat31

gnashley 02-17-2011 03:53 AM
Actually 'case' is much much faster than even simple matching using 'if', and
can even do pattern and glob matching:
Code:
#!/bin/sh

thisString="1 2 3 4 5"
searchString="1 2"
# if you single quote your input, you could do this
# searchString=$1

case $thisString in
  # match exact string
  "$searchString") echo yep, it matches exactly;;
 
  # match start of string
  "$searchString"*) echo yep, it matches at the start ;;

  # match end of string
  *"$searchString") echo yep, it matches at the end ;;

  # searchString can be anywhere in thisString
  *"$searchString"*) echo yep, it matches in the middle somewhere ;;
 
  *) echo nope ;;
esac

lastsurvivor 03-06-2012 03:54 AM
Thanks brother !

Quote:
Originally Posted by gnashley (Post 4261310)
Actually 'case' is much much faster than even simple matching using 'if', and
can even do pattern and glob matching:
Code:
#!/bin/sh

thisString="1 2 3 4 5"
searchString="1 2"
# if you single quote your input, you could do this
# searchString=$1

case $thisString in
  # match exact string
  "$searchString") echo yep, it matches exactly;;
 
  # match start of string
  "$searchString"*) echo yep, it matches at the start ;;

  # match end of string
  *"$searchString") echo yep, it matches at the end ;;

  # searchString can be anywhere in thisString
  *"$searchString"*) echo yep, it matches in the middle somewhere ;;
 
  *) echo nope ;;
esac

OldManRiver 03-17-2015 07:26 PM
Hidden Files don't work
 
All,

I'm trying to read files and directories in a hidden directory.

EX:
Working with ThunderBird EMail client where it resides in:

/home/user/.thunderbird

The 2 things in this directory are:

DIR==> encryptedname.default
FILE=> profile.ini

I either need to pull this directory name directly or read it from the file where file contents are something like:

*********************************************************
[General]
StartWithLastProfile=1

[Profile0]
Name=default
IsRelative=1
Path=encryptedname.default
*********************************************************

Anyway always get error:

Invalid file or directory

when trying to read either. Tried cat, grep, find, etc. always get the same error.

Could use some help around this roadblock!

Cheers!

OMR


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