[SOLVED] Sed Command

gaurvrishi · 04-09-2015, 10:22 AM

Hi,

I am not able to replace the $@@$ with ,. below is the content in which i want $@@$ should be replace with ,

"Harbola$@@$ Gopal (ssoid)","agaga"
"Gaurav$@@$ Gaurav (ssoid)","abc"

so that the result can come like this.

"Harbola, Gopal (ssoid)","agaga"
"Gaurav, Gaurav (ssoid)","abc"

Can anyone help me in this

Lnthink · 04-09-2015, 10:33 AM

"Harbola$@@$ Gopal (ssoid)","agaga"
"Gaurav$@@$ Gaurav (ssoid)","abc"

so that the result can come like this.

"Harbola, Gopal (ssoid)","agaga"
"Gaurav, Gaurav (ssoid)","abc"

sed "s/\\$\@\@\\$/,/" < inputfile > outputfile will do it.

gaurvrishi · 04-09-2015, 10:44 AM

Thanks a lot. Its working fine

grail · 04-09-2015, 01:41 PM

You can reduce the number of escapes by placing the command in single quotes. Also, the @ symbol does not require escaping.

Lnthink · 04-09-2015, 03:34 PM

Quote:

Originally Posted by grail

You can reduce the number of escapes by placing the command in single quotes. Also, the @ symbol does not require escaping.

I tried it without escaping the @ symbols. It seemed to need it for it to work correctly.
Yes, I was surprised by this...

ntubski · 04-09-2015, 03:47 PM

$@ needs escaping from the shell if it's in double quotes.

Code:

# WRONG: 1 backslash protects from shell escaping, but $ needs to be escaped for sed too
"\$@" -> $@
# WRONG: 1st backslash escapes 2nd one (shell escaping rules for double quoted backslashes are confusing)
"\\$@" -> \
# RIGHT: 1st backslash escapes 2nd one, 3rd escapes $; 1 backslash makes it through to escape the $ for sed
"\\\$@" -> \$@

All of this can be avoided by using single quotes.

Lnthink · 04-10-2015, 08:25 AM

Thanks for the single quote tip for sed expressions - I didn't know that.
This will help greatly in the future.

I appreciate it!