If my variable has data as,
test="score=5,grade=d,pass=f,"
Anyway I can extract the data/rewrite the data from/into the variable as,
test="score,grade,pass"
I do not need the data between =, &, and , characters.
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I do not need the data between "=" and ","Noobie– Noobie2015-07-28 10:26:05 +00:00Commented Jul 28, 2015 at 10:26
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2 Answers
In pure bash (no external tools like sed or awk or perl required), you can use "Parameter Expansion" to manipulate strings. You can read about this in Bash's man page.
#!/usr/bin/env bash
test="score=5,grade=d,pass=f,"
# Use the "extglob" shell option for "extended" notation on patterns.
shopt -s extglob
# First, remove the bits from equals to before each comma...
test="${test//=+([^,]),/,}"
# Next, remove the trailing comma.
test="${test%,}"
echo "$test"
And here's a demo.
3 Comments
Noobie
Wow, that works! As I am very new to unix, could you please explain how it works? Would help me frame my own statements for any similar issues in future
ghoti
@Noobie, I added comments to this to help explain the various steps. If the patterns are what you need help with, the best place to start is the "Parameter Expansion" section of the Bash man page. You can search that page for "extglob" as well, for a detailed description of how this works and what the options are.
ghoti
I'm very glad I could help. :-) If this solved your problem, please feel free to click the checkmark beside my answer, to mark this question as answered!
You may use sed.
echo "score=5,grade=d,pass=f," | sed 's/=[^,]*\(,$\|\)//g'
or
echo "score=5,grade=d,pass=f," | sed 's/=[^,]*\|,$//g'
6 Comments
Noobie
I am not able to get the same results in my terminal, It just displays the entire string back to me. Any reason why it could be happening?
Noobie
Sorry, but the new one gave me the same results
Noobie
I am running it in bash
ghoti
I see that this works in GNU sed, but neither of these works in FreeBSD or OSX. You could use the sed script
's/=[^,]*,/,/g;s/,$//' instead. This has pretty much nothing to do with bash.ghoti
@User112638726, per
re_format(7) or regex(7) (depending on your OS), the vertical bar is a regular character in BRE. The fact that its ERE functionality can be found in some RE parsers is non-standard and not universal. One option would be to use ERE instead of BRE, i.e. sed -E 's/=[^,]*|,$//g' (or -r for GNU sed and some other implementations). Of course, implementations vary. Use what works. :) |