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I would like to replace $fileWithPath in $file, however this not works because (I think) path is not escaped. how to escape it?

sed -i 's/${fileWithPath}/HAHA/g' $file

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up vote 42 down vote accepted
sed -i 's|'$fileWithPath'|HAHA|g' file

Single quotes define a string literal. Putting the variable outside the literal allows the shell to expand that part.

Also: if you are going to parse paths, use a delimiter in the sed command that doesn't confuse with the directory delimiter "/".

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Beware that if $fileWithPath contains whitespace, the wrong pattern is inserted. – Lekensteyn Nov 7 '11 at 18:09
Your bonus tip about changing the delimiter for file paths was a life saver! – Shadoninja May 11 at 23:55

In circumstances where the replacement string or pattern string contain slashes, you can make use of the fact that GNU sed allows an alternative delimiter for the substitute command. Common choices for the delimiter are the pipe character | or the hash # - the best choice of delimiting character will often depend on the type of file being processed. In your case you can try

sed -i 's#'$fileWithPath'#HAHA#g' $file

The character 'g' after last # is used to change all occurrences in file if you need to change only first occurrence then remove the 'g'.

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A better way for literal strings with forward slashes:

sed -i "s|my/path|my/other/path|g" myFileOfPaths.txt
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