weird sed

[Qing Zhu]

OS: tru64unix V4.0G, Shell: csh
# which sed
/usr/bin/sed
# echo "a b" | sed 's/ /\t/'
atb

???
I am expecting a TAB between "a" and "b", not "atb", what am I doing wrong?
Seems sed won't recognize all escape sequences such as \n,\t,\r,\b ...
Anyone have comment on this? much appreciated.

[Qing Zhu]

# echo "a b" | sed 's/ /\\\t/'
a\tb

Also not what I wanted :-(

[Hein van den Heuvel · Accepted solution]

I think that the \t convention is unfortunately for output only.

For input, just type in a tab!


a reference in this area:

http://www.unixguide.net/unix/sedoneliner.shtml
:
"USE OF '\t' IN SED SCRIPTS: For clarity in documentation, we have used
the expression '\t' to indicate a tab character (0x09) in the scripts.
However, most versions of sed do not recognize the '\t' abbreviation,
so when typing these scripts from the command line, you should press
the TAB key instead. '\t' is supported as a regular expression
metacharacter in awk, perl, and in a few implementations of sed. "

Hein.

[Qing Zhu]

Thanks Hein.