The easiest way is to use sed (or perl):
sed -i -e 's/abc/XYZ/g' /tmp/file.txt
Which will invoke sed to do an in-place edit due to the -i
option. This can be called from bash.
If you really really want to use just bash, then the following can work:
while read a; do
echo ${a//abc/XYZ}
done < /tmp/file.txt > /tmp/file.txt.t
mv /tmp/file.txt{.t,}
This loops over each line, doing a substitution, and writing to a temporary file (don't want to clobber the input). The move at the end just moves temporary to the original name.
For Mac users:
sed -i '' 's/abc/XYZ/g' /tmp/file.txt
(See the comment below why)
As of August 2020: Modern browsers have support for the String.replaceAll()
method defined by the ECMAScript 2021 language specification.
For older/legacy browsers:
str = str.replace(/abc/g, '');
In response to comment:
var find = 'abc';
var re = new RegExp(find, 'g');
str = str.replace(re, '');
In response to Click Upvote's comment, you could simplify it even more:
function replaceAll(str, find, replace) {
return str.replace(new RegExp(find, 'g'), replace);
}
Note: Regular expressions contain special (meta) characters, and as such it is dangerous to blindly pass an argument in the find
function above without pre-processing it to escape those characters. This is covered in the Mozilla Developer Network's JavaScript Guide on Regular Expressions, where they present the following utility function (which has changed at least twice since this answer was originally written, so make sure to check the MDN site for potential updates):
function escapeRegExp(string) {
return string.replace(/[.*+\-?^${}()|[\]\\]/g, '\\$&'); // $& means the whole matched string
}
So in order to make the replaceAll()
function above safer, it could be modified to the following if you also include escapeRegExp
:
function replaceAll(str, find, replace) {
return str.replace(new RegExp(escapeRegExp(find), 'g'), replace);
}
Best Answer
You want to use postgresql's replace function:
for instance :
Be aware, though, that this will be a string-to-string replacement, so 'category' will become 'dogegory'. the regexp_replace function may help you define a stricter match pattern for what you want to replace.