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I know this has been asked before but I'm having trouble understanding the answers I've found. Basically I want to use

sed -i 's/string//some/directory/g' file.txt

and I can't find a straight answer on how to make /some/directory not break up the sed syntax.

AdminBee
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Justanothermatt
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3 Answers3

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sed allows several syntax delimiters, / being only the one most commonly used.

You can just as well say

sed -i 's,<string>,<some/directory>,g' file.txt

where the , now has the function usually performed by the /, thereby freeing the latter from its special meaning.

Note, however (as pointed out by @Jeff Schaller), that now the , must not appear in the file or directory name - and it is a valid character for filenames! This answer gives a good overview on how to proceed when applying sed to a string with special characters.

AdminBee
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6

Replacing the delimiter with one that is known not to appear in the search or replace strings is a good option when you can find a delimiter that does not appear in them. I tend to use the plus sign, rather than a comma, but that's a matter of habit more than anything.

However, if you can't find a delimiter that doesn't appear in the string, there's always backslash-escaping:

sed -e 's/<string>/<some\/directory>/g' file.txt

The \ in front of the slash lets sed know that it's just a slash and not a delimiter.

Joey Marianer
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  • I sometimes find I must resort to back-slash escaping within a sed expression, but usually find I can use a delimiter not contained in the expression. My common delimiters, other than the / are the tilde ~, plus sign + and equals sign =. Don't think I've ever used a comma , or octothorp # – dave58 Sep 14 '20 at 02:02
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@AdminBee I have only seen the # used as delimiter so far, guess it appears less often in the patterns than a comma:

sed -i 's#<string>#<some/directory>#g' file.txt
AdminBee
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patrice
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