Using sed to replace the same text line in multiple files

Question

In my current directory (projDir), I have about 41 folders as follows:

ProgOneDir
ProgTwoDir
ProgThreeDir
...
ProgFortyOneDir

...etc (I did not come up with the naming scheme and I am not a systems admin so please don't yell at me for them).

Inside each of the subfolders, there are README.md files I need to edit. Instead of going into each subfolder and editing the files there, I would like to use a sed command to do so. The files are consistently named README.md

I am running CentOS7

My current command is:

find . -name 'README.md' -exec sed -i -e 's/./makeprog $MAKE_FLAGS CFLAGS="-I/usr/local/include/libtool" OFLAGS="-L/usr/local/lib"/./makeprog/g' {} \;

Essentially, I need to switch:

./makeprog $MAKE_FLAGS CFLAGS="-I/usr/local/include/libtool" OFLAGS="-L/usr/local/lib

to

./makeprog

Would somebody be able to assist? The error I get is:

sed: -e expression #1, char 43: unknown option to `s'

I have already looked at:

Using sed to replace text between strings
How to replace a path with another path in sed?
Some other online resources

I believe my error is arising with the ./command. I have followed advice of switching all / to +, but that still didn't work, as I got the following error:

sed: -e expression #1, char 110: unterminated `s' command

Thank you.

Hi @kvantour, I don't think it is. I saw that, but it isn't explicitly paths I'm concerned with, it is switching a command that contains ./ I found that article and tried following the advice of switching / to + and it still didn't work. — artemis
– artemis, Commented Oct 17, 2018 at 13:12
Basically you alreay have the correct command. Only failure: The slash character is part of your "pattern", that's why you either must escape it or use another "separator" for sed, for example the # char: sed 's#./makeprog $MAKE_FLAGS CFLAGS="-I/usr/local/include/libtool" OFLAGS="-L/usr/local/lib"#./makeprog#g' — rudi
– rudi, Commented Oct 17, 2018 at 13:13
The slashes give you the error 'unknown option to s`. The other problem is your dollar sign. You have to escape them. — kvantour
– kvantour, Commented Oct 17, 2018 at 13:14
@kvantour $ signs don't matter as long as using single quotes. — rudi
– rudi, Commented Oct 17, 2018 at 13:14
@kvantour: that's true if $ is at the end of the regexp. otherwise it's considered as a normal character. — rudi
– rudi, Commented Oct 19, 2018 at 14:34

glenn jackman · Accepted Answer · 2018-10-17 13:17:14Z

6

Your problem is that you are using slash as the delimiter to the s/// command, but you are putting slashes into the pattern. You can pick a different delimiter that does not appear in the pattern.

Assuming your current directory is projDir, and there is only one call to makeprog:

sed -i -E 's#(./makeprog) .*#\1#' */README.md

or

perl -i -e 's{./makeprog\K.*}{}' */README.md

If you want to specifically match that exact line, then:

# are you missing a trailing double quote?
line='./makeprog $MAKE_FLAGS CFLAGS="-I/usr/local/include/libtool" OFLAGS="-L/usr/local/lib'
sed -i -E "s#$line#./makeprog#" */README.md

edited Oct 17, 2018 at 13:17

answered Oct 17, 2018 at 13:14

glenn jackman

249k42 gold badges233 silver badges362 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

artemis Over a year ago

Hi @glenn jackman, thank you for your answer. This worked perfectly. Might you be able to explain what the .*#\1# is doing, so that I may learn?

glenn jackman Over a year ago

On the left hand side, the regex pattern, I put parentheses around (./makeprog). In the right hand side, the replacement string, you can use \n to use the text matched in the nth parenthesised group. For documentation see 3.3 The s Command

Collectives™ on Stack Overflow

Using sed to replace the same text line in multiple files

1 Answer 1

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related