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How can I search and replace text that contains / with sed?

I currently use the following command which doesn't work

sed -i "s/queue_directory = /var/spool/postfix-secondary/queue_directory = /var/spool/postfix-$newnumber/g" /etc/postfix-$newnumber/main.cf
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    backslash escape it when not a delimiter or swap delimiters: s|queue_directory = /var/spool.*|newnumber|. – mikeserv Jul 2 '15 at 22:27
  • What's the full command for that? – Teddy291 Jul 2 '15 at 22:33
  • @WhimsicalWombat - it just feels... cheap. But you're welcome to, and guaranteed at least one upvote if you ping me when through. Teddy - wherever you do s/// the stuff between those comprise the address and replace fields. If the stuff contains / then you just have to use something else like s|||, or backslash escape the stuff within like s/\///. It works for regular addresses too, but those always require a backslash when not / like: sed '\|^/|s/.//' which will remove a / if it occurs at the head of a line. And so the full command is your command where s/// is s||| instead. – mikeserv Jul 2 '15 at 22:42
  • For more info about regex visit gnu.org/software/sed/manual/html_node/Regular-Expressions.html and to try what you want with a little explanation visit regexr.com – tachomi Jul 2 '15 at 23:20
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One approach is to pick a different delimiter besides /. For example, using |:

sed -ie "s|queue_directory = /var/spool/postfix-secondary|queue_directory = /var/spool/postfix-$newnumber|g" /etc/postfix-$newnumber/main.cf

Another approach is to backslash-escape your other slashes:

sed -ie "s/queue_directory = \/var\/spool\/postfix-secondary/queue_directory = \/var\/spool\/postfix-$newnumber/g" /etc/postfix-$newnumber/main.cf

Two more suggestions for your particular usage. First, I don't think you need the g flag, unless you anticipate the substitution appearing multiple times in the same line. Second, if you are just trying to change a directive, you could potentially just change it no matter what the previous value. For example:

sed -ie "s|^queue_directory =.*|queue_directory = /var/spool/postfix-$newnumber|" /etc/postfix-$newnumber/main.cf

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