Reputation: 6965
I have this shell script variable, var. It keeps 3 entries separated by new line. From this variable var, I want to extract 2, and 0.078688. Just these two numbers.
var="USER_ID=2
# 0.078688
Suhas"
These are the code I tried:
echo "$var" | grep -o -P '(?<=\=).*(?=\n)' # For extracting 2
echo "$var" | awk -v FS="(# |\n)" '{print $2}' # For extracting 0.078688
None of the above working. What is the problem here? How to fix this ?
Upvotes: 2
Views: 1142
Reputation: 5724
You can do it with pure bash using a regex:
#!/bin/bash
var="USER_ID=2
# 0.078688
Suhas"
[[ ${var} =~ =([0-9]+).*#[[:space:]]([0-9\.]+) ]] && result1="${BASH_REMATCH[1]}" && result2="${BASH_REMATCH[2]}"
echo "${result1}"
echo "${result2}"
Upvotes: 1
Reputation: 10039
Assuming this is the format of data as your sample
# For extracting 2
echo "$var" | sed -e '/.*=/!d' -e 's///'
echo "$var" | awk -F '=' 'NR==1{ print $2}'
# For extracting 0.078688
echo "$var" | sed -e '/.*#[[:blank:]]*/!d' -e 's///'
echo "$var" | awk -F '#' 'NR==2{ print $2}'
Upvotes: 0
Reputation: 2121
With awk:
First value:
echo "$var" | grep 'USER_ID' | awk -F "=" '{print $2}'
Second value:
echo "$var" | grep '#' | awk '{print $2}'
Upvotes: 0
Reputation: 85895
Just use tr
alone for retaining the numerical digits, the dot (.
) and the white-space and remove everything else.
tr -cd '0-9. ' <<<"$var"
2 0.078688
From the man
page, of tr
for usage of -c
, -d
flags,
tr [OPTION]... SET1 [SET2]
-c, -C, --complement use the complement of SET1
-d, --delete delete characters in SET1, do not translate
To store it in variables,
IFS=' ' read -r var1 var2 < <(tr -cd '0-9. ' <<<"$var")
printf "%s\n" "$var1"
2
printf "%s\n" "$var2"
2
0.078688
Or in an array as
IFS=' ' read -ra numArray < <(tr -cd '0-9. ' <<<"$var")
printf "%s\n" "${numArray[@]}"
2
0.078688
Note:- The -cd
flags in tr
are POSIX
compliant and will work on any systems that has tr
installed.
Upvotes: 5
Reputation: 18411
echo "$var" |grep -oP 'USER_ID=\K.*'
2
echo "$var" |grep -oP '# \K.*'
0.078688
Your solution is near to perfect, you need to chance \n
to $
which represent end of line.
echo "$var" |awk -F'# ' '/#/{print $2}'
0.078688
echo "$var" |awk -F'=' '/USER_ID/{print $2}'
2
Upvotes: 2