Context in HPUX grep

[wojtek75]

HPUX B.11.11

Hi,

is there any command in HPUX that can work like GNU grep that shows context lines (a few lines preceeding and succeeding the selected line)? It looks like HPUX grep can't do that. Thank you in advance.

[Pete Randall · Accepted solution]

You can do it with sed:

# print 1 line of context before and after regexp, with line number
# indicating where the regexp occurred (similar to "grep -A1 -B1")
sed -n -e '/regexp/{=;x;1!p;g;$!N;p;D;}' -e h

Taken from Handy One-Liners for SED (attached).


Pete

[wojtek75]

Thanks, great but hard to understand without basic knowledge of sed. How can I get only one line before matching line?

[James R. Ferguson]

Hi:

For that matter, you could fetch and install GNU's 'grep' from the HP-UX Porting Center:

http://hpux.asknet.de/hppd/hpux/Gnu/grep-2.5.3/

Regards!

...JRF...

[wojtek75]

Hi,

sed is OK. I would appreciate the final sed command that prints only preceding line and doesn't print line numbers. How can I get it?

[Patrick Wallek]

The following will print the line with the regexp and the line preceding:

sed -n -e '/regexp/{x;1!p;g;p;}' -e h filename

[wojtek75]

Thanks,

and is it possible to join these two lines together? I would like to have a preceding and matching line printed in one line.

[James R. Ferguson]

Hi:

> and is it possible to join these two lines together? I would like to have a preceding and matching line printed in one line.

# sed -n -e '/b/{x;1!p;g;p;}' -e h filename|paste -- - -

That's a double dash; whitespace; a single dash; whitespace; and another single dash.

Regards!

...JRF...

[Dennis Handly]

>I would like to have a preceding and matching line printed in one line.

Modifying JRF's solution you can go sed crazy and do:
sed -n -e '/regexp/{H;g;s/\n/ /;p;}' -e h filename

(Note: It doesn't work too well if the pattern is on two sequential lines.)