Replace names in git log using sed on MacOs (for Gource) - regex

Question

I'm trying to make a nice Gource video on our software develop project. Using Gource a can generate a combined git log of all repos with:
first gource --output-custom-log ../logs/repo1.txt then
cat *.txt | sort -n > combined.txt
This generates a combined.txt file which is a pipe delimited file like:
1551272464|John|A|repo1/file1.txt
1551272464|john_doe|A|repo1/folder/file9.py
1551272464|Doe, John|A|repo2/filex.py
So its: EPOCH|Committer name|A or D or C|committed file
The actual problem I want to solve is the fact that my developers have used different git clients with different committer names so id like to replace all of their names to a single version. I do not mind setting multiple sed per situation.
So find "John", "john_doe" and "Doe, John" and replace it with "John Doe". And it should be done on my MacBook.
So I tried sed -i -r "s/John/user_john/g" combined.txt but the problem here is that it finds "John" and "Doe, John" and replaces just the "John" part so I'm need to do a fuzzy search and replace the whole column.
Who can help me get the correct regex?

Answer 1

A regex would almost certainly be the wrong approach for this as you'd get false matches unless you were extremely careful and it's inefficient.
Just create an aliases file containing a line for each name you want in your output followed by all the names that should be mapped to it and then you can do this to change them all clearly, simply, robustly, portably, and efficiently in one call to awk:
$ cat tst.awk
BEGIN { FS="[|]" ; OFS="|" }
NR==FNR {
for (i=2; i<=NF; i++) {
alias[$i] = $1
}
next
}
$2 in alias { $2 = alias[$2] }
{ print }
.
$ cat aliases
John Doe|John|john_doe|Doe, John
Susan Barker|Susie B|Barker, Susan
.
$ cat file
1551272464|John|A|repo1/file1.txt
1551272464|Susie B|A|repo2/filex.py
1551272464|john_doe|A|repo1/folder/file9.py
1551272464|Doe, John|A|repo2/filex.py
1551272464|Barker, Susan|A|repo2/filex.py
.
$ awk -f tst.awk aliases file
1551272464|John Doe|A|repo1/file1.txt
1551272464|Susan Barker|A|repo2/filex.py
1551272464|John Doe|A|repo1/folder/file9.py
1551272464|John Doe|A|repo2/filex.py
1551272464|Susan Barker|A|repo2/filex.py

Answer 2

As #WiktorStribizew mentioned, you can do:
sed -i -r "s/Doe, John|john_doe|John/user_john/g" combined.txt
And with that, you can even do:
sed -i -r -e "s/Doe, John|john_doe|John/user_john/g" -e "s/Wayne, Bruce|bruce_wayne|Bruce/user_bruce/g" combined.txt
And add more replacements to chain with the -e option:
-e script, --expression=script
add the script to the commands to be executed

Answer 3

try gnu sed:
sed -E "s/^(\w+\|)(john([\s_]doe)?|doe,\s*john)/\1John Doe/i" combined.txt
add -i option after examining to edit it; sed -Ei...