Shell Programming and Scripting

Greetings!

Well, this next example should be a snap, but, instead, sed is raising yet another bump on my head. Here's the "offending" commandline today:

Code:

sed -i s'/\$\{HOUSING\}/casing/g' ./some.file

And, here's the output:

Code:

sed: -e expression #1, char 27: Invalid content of \{\}

FWIW, I tried substituting "/" with "%"

Code:

sed -i s'%\$\{HOUSING\}%casing%g' ./some.file

but that didn't work, either...

Quick help, anyone???


Thanks!

The only thing in that expression you need to escape is $, which to sed means 'end of line'.

Code:

$ echo '${HOUSING}'

${HOUSING}

$ echo '${HOUSING}' | sed 's/\${HOUSING}/casing/g'

casing

$

Maybe,

Code:

sed -ie "s/${HOUSING}/casing/g" ./some.file

Since they were trying to escape { I'm guessing they intended to replace the literal string ${HOUSING}, and not the variable expansion of ${HOUSING}.

Hard to say, even the single quotes are not correct.

Code:

s'/\$\{HOUSING\}/casing/g'

Thanks for the help. Corona688 nailed it; just was making more work for myself than I needed to . . . Don't remember where I picked up this way of quoting, but

Code:

sed -i s'/\${HOUSING}/casing/g' ./some.file

is fully functional, too...

Am I just "lucky" here, or is there something else to know?

Thanks again --

You want to surround any command to another program like sed, awk, perl, etc with single quote to protect the content from the shell interpretation. The reason why it works there for you is that the `s' for sed's substitution operator does not have any special meaning to the shell.
One place I see most people stumble is when trying to do variable expansion inside sed, thus why I used the double quotes so the shell can see it as a variable.