I am trying to match all characters of given string but those characters should match in the order as given to the bash script.
while [[ $# -gt 0 ]]; do
case $1 in
-i)
arg=$2
egrep "*[$arg]*" words.txt
shift ;;
esac
shift
done
$ sh match_the_pattern.sh -i aei words.txt
Should return words like
abstentious
adventitious
sacrilegiousness
If you notice, first a is matched then e and then i, all of them are in order. Plus, the whole word is matched and filtered.
Change this:
arg=$2
egrep "*[$arg]*" words.txt
to this:
arg=$(sed 's/./.*[&]/g' <<< "$2")
grep "$arg" words.txt
If that's not all you need then edit your question to clarify your requirements and provide more truly representative sample input/output.
You may use getopts with some bash parameter substitution to construct the query string.
#!/bin/bash
while getopts 'i:' choice
do
case "${choice}" in
i)
length=${#OPTARG}
for((count=0;count<length;count++))
do
if [ $count -eq 0 ]
then
pattern="${pattern}.*${OPTARG:count:1}.*"
else
pattern="${pattern}${OPTARG:count:1}.*"
fi
done
;;
esac
done
# The remaining parameter should be our filename
shift $(($OPTIND - 1))
filename="$1"
# Some error checking based on the parsed values
# Ideally user input should not be trusted, so a security check should
# also be done,omitting that for brevity.
if [ -z "$pattern" ] || [ -z "$filename" ]
then
echo "-i is must. Also, filename cannot be empty"
echo "Run the script like ./scriptname -i 'value' -- filename"
else
grep -i "${pattern}" "$filename"
fi
Refer this to know more on parameter substitution and this for getopts.
Your regex is matching 'a' or 'e' or 'i' because they are in a character set ([]).
I think the regular expression you are looking for is
a+.*e+.*i+.*
which matches 'a' one or more times, then anything, then 'e' one or more times, then anything, then 'i' one or more times.
