I am looking how to bash script a hostname and grab everything in between numbers into a var. For example, let's say the hostname is abcd1efghij12kl. How do return just efghij?
The number of letters before the first number varies and the number of letters after the second number can vary and inbetween.
Also to first number could be 1 or 2 digits and same for the second set of numbers. I am looking to get only the letters in between. When I try IFS i can't seem to get anywhere. Thanks
Here's 2 ways to do it with bash:
hostname=abcd1efghij12kl
# using a subshell so the IFS and options don't affect your running shell
(IFS=0123456798; set -f; set -- $hostname; echo "$2")
# => efghij
# using a regular expression and the BASH_REMATCH array
if [[ $hostname =~ [[:digit:]]([^[:digit:]]+)[[:digit:]] ]]; then
echo "${BASH_REMATCH[1]}"
fi
# => efghij
The key is that IFS is a "set" of characters, not a pattern. If you tried IFS="[0-9]", then bash will try to split using the 5 characters [, 0, -, 9, ]
hostname=$(hostname)PATH=something and then wonder why your script is broken.You can use parameter expansions in bash (extended globbing needed):
#! /bin/bash
shopt -s extglob # Turn on extended globbing
for hostname in abcd1efghij12kl abcd12efghij12kl abcd12efghij2kl abcd1efghij1kl ; do
between_digits=${hostname##+([^0-9])+([0-9])} # Remove everything up to the first number
between_digits=${between_digits%%[0-9]*} # Remove everything starting from the last number
echo "$between_digits"
done
Using sed:
echo "abcd1efghij12kl"| sed -E 's/.*[[:digit:]]([^[:digit:]]+)[[:digit:]].*/\1/g'
Output:
efghij
[ in ([^[[:digit:]]+), resulting in ([^[:digit:]]+). Teststring: abcd1ef[ghij12kl.