How to search and replace text files with "/"

Question

I have a text file with ./. and need to replace it with 0|0.

The file is too big to open in Gedit and do it by hand.

Can I do it using sed?

Answer 1

Yes. In this case it's useful to choose a different delimiter like _, this way you don't have to escape the slash:

sed 's_\./\._0|0_'

Example:

$ cat test
./.
$ sed 's_\./\._0|0_' test
0|0

Add

• -i to change the file in place rather than print the output to stdout,
• -i.b to do so and save a backup with .b as an extension and
• g to the end of the expression to change multiple occurences per line rather than just the first one (→ 's_\./\._0|0_g').

Explanations

• s/A/B/ – replace A by B, the same as s_A_B_, ssAsBs or whatever you can imagine:

  Any character other than backslash or newline can be used instead of a slash to delimit the BRE and the replacement. ^[source]

• s/A/B/g – replace A by B and do it globally, so don't stop doing it after the first finding (per line!)

• \./\. – the literal string ./., a dot needs to be escaped with a backslash because they are part of basic regular expressions and else would take any character, matching a/a, a/b, /// and so on
• 0|0 – the literal string 0|0

Answer 2

Yes, you can do that with sed.
You need to escape . and / with a \.

sed -i.bak 's/\.\/\./0|0/g' file

-i.bak will make sed edit the file in place but creates a backup file with .bak extension.
The g at the end means "global" --> Replaces all occurencies.

Answer 3

Even though you asked for sed command to fulfill your requirement, you can also give a try to ex command.

ex -sc '%s/\.\/\./0|0/g|x' file

% select all lines

s for substitute

g replace all instances globally

x write if changes made and exit

Example:-

$cp file file.bak
$cat file
./.
$ex -sc '%s/\.\/\./0|0/g|x' file
$cat file
0|0