extract value between two search patterns on same line

I have the following in a file Output.dat. I need to extract the value between dn: uid= and ,ou=

 dn: uid=user1,ou=Active,ou=Member,dc=domain,dc=org
 dn: <a href="https://getridbug.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="592c303d642c2a3c2b6b19383b3a773a3634">[email protected]</a>,ou=Active,ou=Member,dc=domain,dc=org
 dn: uid=usertest,ou=Active,ou=Member,dc=domain,dc=org
 dn: uid=abc1,ou=Active,ou=Member,dc=domain,dc=org

• I tried using

  sed -e '/dn: uid=/,/,ou=/p' output.dat but

  it returns complete line instead of value.

• When tried to use

  sed -e '/dn: uid=/,/,ou=/1/p' output.dat

  then got the following error:

  sed: -e expression #1, char 18: unknown command: `'

Answers:

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Method 1

If you have a version of GNU grep with PCRE (-P) support, then assuming you mean the first occurrence of ,ou

grep -oP '(?<=dn: uid=).+?(?=,ou=)' file

If you want to match up to the second ,ou you can remove the non-greedy ? modifier

grep -oP '(?<=dn: uid=).+(?=,ou=)' file

The expressions in parentheses are zero-length assertions (aka lookarounds) meaning that they form part of the match, but are not returned as part of the result. You could do the same thing natively in perl e.g.

perl -ne 'print "$1n" if /(?<=dn: uid=)(.+?)(?=,ou=)/' file

It’s possible to do something similar in sed, using regular (non zero-length) grouping e.g. (for GNU sed – other varieties may need additional escaping)

sed -rn 's/(.*dn: uid=)([^,]+)(,ou=.*)/2/p' file

or simplifying slightly

sed -rn 's/.*dn: uid=([^,]+),ou=.*/1/p' file

Note the [^,] is a bit of a hack here, since sed doesn’t have a true non-greedy match option.

Afterthought: although it’s not exactly what you asked, it looks like what you actually want to do is read comma-separated name=value pairs from a file, and then further split the value of the first field from its name. You could achieve that in many ways – including

awk -F, '{sub(".*=","",$1); print $1}' file

or a pure-bash solution such as

while IFS=, read -r a b c d; do printf '%sn' "${a#*=}"; done < file

Method 2

This is a good job for awk. You can split the string instead of attempting to use a regex. Here is a solution:

$ awk -F= '{ split($2,arr,","); print arr[1]  }' test.txt
user1
<a href="https://getridbug.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="bfcaccdacd8dffdedddc91dcd0d2">[email protected]</a>
usertest
abc1

Method 3

With sed:

sed 's/[^=]*=([^,]+),.*/1/' file

This assumes the uid= will have the first occurrence of = on the line and it assumes that you want to stop at the first ,ou= instance on the line.

Explanation

This looks for any number of non = characters ([^=]*) followed by = then matches and saves as many non-commas as it can find ( ([^,]+) ) followed by a comma and the rest of the line (,.*). This means it will replace everything up to and including the first = and after the first comma with whatever non-comma characters it finds after the first = on the line.

Method 4

Some more choices, in order of length:

1. GNU grep with PCREs

   grep -oP 'uid=K[^,]+' file

   The K discards everything matched up to that point, which combined with the -o switch will cause grep to print only the longest stretch of non , characters that comes after the uid=.

2. awk

   awk -F'[=,]' '{print $2}' file

   -F'[=,] sets the field separator to be either = or , so the 2nd field is the user name.

3. sed

   sed -r 's/.{8}([^,]*).*/1/' file

   That will match the first 7 characters (.{7}) =, capture the longest stretch of non-, as 1 and replace the whole line with 1.

4. perl

   perl -pe 's/.+?=([^,]+).*/$1/' file

   The -pe means “print every line after applying the script given by -e”. The s/// is the substitution operator and the regular expression looks for the 1st (.+?, the ? makes it match the shortest possible string) = and then captures the longest stretch of non-, characters after that. The s/// replaces what was matched with what was captured (what was inside the parentheses).

5. cut

   cut -d'=' -f 2 file | cut -d ',' -f 1

   The -d sets the delimiter to = so the 2nd (-f 2) field is username,ou. The second cut uses , as delimiter and prints the username alone.

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0