Issue
I have an curl output as below and i need to grep only the numbers from that output.
Curl Output
<h1>JVM</h1><p>Free Memory:2144.78 MB Total Memory:3072.00 MB Max Memory:3072.00 MB</p><table border="0">
Grep Command
grep -o -i 'Max Memory:.*' | awk '{ print $3 }'
Output
MB</p><table
Expected Output : 3072.00
Similarly for Free Memory and Total Memory.
Please help
Solution
1st solution: With your shown samples, please try following in GNU grep.
grep -oP 'Total Memory:\K\S+' Input_file
OR in case you want to match exact digits which are coming for memory value then try following:
grep -oP 'Total Memory:\K\d+(?:\.\d+)?(?=\s)' Input_file
Explanation: Simple explanation would be, using GNU grep's -o and -P options firstly. To print only matched text and to enable PCRE regex flavor. Then in main grep program using regex to match Total Memory: to be searched followed by \K which means if previous match is found then forget the match. Then matching \S+ means match everything non-space(s) before a space comes which will catch value for Total memory.
2nd solution: In case you want to get 3 values in output for free memory, max and total ones then try following awk code. Written and tested in GNU awk.
awk -v RS='(Free Memory:|Total Memory:|Max Memory:)[^[:space:]]+' 'RT{sub(/.*:/,"",RT);print RT}' Input_file
NOTE: In case your output is not in an Input_file then you can use pipe to your previous command and then run this one.
Answered By - RavinderSingh13 Answer Checked By - Pedro (WPSolving Volunteer)