bash function to replace every occurence of text in directory and subdirectories

Question

I found (on Google) this perfectly working line to replace every occurences in all files in my directory and subdirectories:

grep -lr previoustext | xargs sed -i 's/previoustext/newtext/g'

It works great.

But now I'm trying to use it in a function in my bash_aliases file as following:

freplace() {
    grep -lr previoustext | xargs sed -i 's/previoustext/newtext/g';
}

However, when I call

freplace previoustext newtext

in my terminal, nothing happens ... . The text is not replaced.

Any idea why it doesn't work ?

Welcome to the site. Please note that the command you use can be a problem if you have filenames that contain special characters (like whitespace), because that can lead to unwanted word splitting (see [this question for reasons](https://unix.stackexchange.com/questions/128985/why-not-parse-ls-and-what-to-do-instead)). If you have the GNU version of the tools installed, it is advisable to use the `-Z` option of `grep` together with the `-0` option of `xargs` to prevent this kind of problems. — AdminBee, Aug 12 '20 at 10:16
`~/bash_alaises` is not a standard file. Are you perhaps using Ubuntu? That's the only system I know of that includes that file by default. What is the output of `grep bash_aliases ~/.bashrc`? More importantly, is that the _exact_ function? Do you already have the strings `previoustext` and `newtext` hardcoded in the function? If so, why are you also passing them to your function as arguments? — terdon, Aug 12 '20 at 10:18

score 2 · Accepted Answer · answered Aug 12 '20 at 10:10

2

If you want to pass arguments to a function, you need to use positional parameters to pick them up.

freplace() {
    grep -lr "$1" | xargs sed -i "s/$1/$2/g"
}

Note that it doesn't work for strings containing / or other characters special to sed.

answered Aug 12 '20 at 10:10

choroba

1

You could mention that the limitation about `/` can in part be circumvented by using one of the other separator characters (`@`,`#`, ...) - well knowing that of course, these can then also not go unescaped. – AdminBee Aug 12 '20 at 10:12
I just forgot to close and reopen the terminal ... thanks, it worked well with the positionnal parameters. – Zkyem Aug 12 '20 at 10:21

1 Answers1