Replace a semicolon followed by a backslash by just a semicolon and dont apply it to other baskslashs alone

Question

I have a file that contains data that looks like this :

WWWWWWWWWWWWWW;XXXXXXXXXXXXXXXXXXXX;ZZZZZZZZZZZZZZ;EE;/usr/lib/systemd/system/snapd.socket
WWWWWWWWWWWWWW;XXXXXXXXXXXXXXXXXXXX;ZZZZZZZZZZZZZZ;EE;/usr/lib/systemd/system/sysinit.target
WWWWWWWWWWWWWW;XXXXXXXXXXXXXXXXXXXX;ZZZZZZZZZZZZZZ;EE;/usr/lib/systemd/system/sysinit\target

Sometimes errors appear in this file, they look like this ;

\WWWWWWWWWWWWWW;\XXXXXXXXXXXXXXXXXXXX;\ZZZZZZZZZZZZZZ;EE;/usr/lib/systemd/system/sysinit\target

As you can see ther is backslashes that makes my file very hard to parse after.

I tried to make them disappeard with :

cat ligne.txt | tr "\\" "\0"

But it affects the file names containing \ and I want to keep the file name the same.

So I tried to use the condition only the \ with a semicolon next to it.

cat ligne.txt | tr ";\\" "\0"

but it gives me this :

WWWWWWWWWWWWWWXXXXXXXXXXXXXXXXXXXXZZZZZZZZZZZZZZEE/usr/lib/systemd/system/sysinittarget

The data is destroyed.

So i tried this :

cat ligne.txt | tr ";\\" ";"

but it does this witch is worst :

\WWWWWWWWWWWWWW;;XXXXXXXXXXXXXXXXXXXX;;ZZZZZZZZZZZZZZ;;EE;;/usr/lib/systemd/system/sysinit;target

This brings me to the the question: how does tr process \\ and ; in parameters ?

score 1 · Accepted Answer · answered Jul 20 '22 at 08:27

1

Try with sed :

cat ligne.txt | sed -e 's/;\\/;/g'

answered Jul 20 '22 at 08:27

GregThB

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You don't need to use `cat` here – Fravadona Jul 20 '22 at 08:38

score 0 · Answer 2 · answered Jul 20 '22 at 08:51

0

Using sed

$ sed -E ':a;s~\\(.*;)~\1~;ta' input_file
WWWWWWWWWWWWWW;XXXXXXXXXXXXXXXXXXXX;ZZZZZZZZZZZZZZ;EE;/usr/lib/systemd/system/sysinit\target

answered Jul 20 '22 at 08:51

HatLess

10,622
5
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While it looks reasonable to me, the OP wants to replace semicolons **followed by a backslash**. You have removed the very first backslah in the line, although it is not preceeded by a semicolon. – user1934428 Jul 20 '22 at 09:11
@user1934428 That may very well be a valid point. However, he does also show the format the file currently is which does not have the preceeding semicolon. Hopefully, OP can clarify then I will adjust accordingly. Thanks – HatLess Jul 20 '22 at 09:17

Replace a semicolon followed by a backslash by just a semicolon and dont apply it to other baskslashs alone

2 Answers2