Picking package names from emerge output

[tmo]

Tired of manually picking package names from emerge output?

emerge-cut-pkg:

Code: Select all

#!/bin/sh
sed -n 's/^[^]]*U \] \+\([^ ]*\).*/=\1/p'

Usage:

Code: Select all

# save list of packages to a tmp file because emerge is dog-slow
$ emerge -puD world | emerge-cut-pkg > /tmp/out

$ cat /tmp/out 
=sys-kernel/linux-headers-2.6.11-r3
=sys-libs/glibc-2.3.5-r3
=x11-libs/xtrans-1.0.0
=x11-libs/libICE-1.0.0
...

# emerge (pretend) only x11-libs/*
$ emerge -pvt `grep x11-libs /tmp/out`

These are the packages that I would merge, in reverse order:

Calculating dependencies ...done!
[ebuild     U ] x11-libs/libXevie-1.0.0 [0.99.3] 201 kB 
[ebuild     U ] x11-libs/libXinerama-1.0.0 [0.99.2] 196 kB 
[ebuild     U ] x11-libs/libXrandr-1.1.0.2 [1.1.0.1] 206 kB 
...

Edited the sed expression to include only updated packages

[roseZ]

Nice idea! I Wonder why I didn't come up with this myself. Maybe I'm still not lazy enough

One question, though: what's the purpose of \+ in the expression? Works without it, too.
I suppose it doesn't match a literal + and I couldn't find an explanation with a few searches
So please, educate me.

[roseZ]

Silly me. It seems to work like I tought + would do alone (match one or more occurrences
of the previous block). I just don't understand why it has to be escaped. Back in the days,
at least Rute used to teach this the other way around.

[tmo]

Silly me. It seems to work like I tought + would do alone (match one or more occurrences
of the previous block). I just don't understand why it has to be escaped. Back in the days,
at least Rute used to teach this the other way around.

Maybe sed got support for '+' later and without escaping it would have broken backward compatibility, I don't know really :)

I wonder why emerge doesn't have an option to output package names only...

[roseZ]

Ok, I did what I should have done right from the start. Read the man page of sed (and grep), that is

Apparently there are two kinds of regexps: basic and extended. Default for sed and grep is the former,
in which characters like ? + ( | { lose their special meaning unless preceded by a backslash.
I think I like the extended mode better, since it's more consistent. Excaping invokes literal meaning
instead of the opposite for all characters.

So we could shave a few characters off the script:

Code: Select all

#!/bin/sh
sed -nr 's/^[^]]*U \] +([^ ]*).*/=\1/p'

This will undoubtedly sacrifice some portability, although \+ is already a GNU extension

About portage tools, they could definitely be polished, but the devs must have their hands full.

[slycordinator]

I like this better:

Code: Select all

#!/bin/sh
sed -n 's/^[^]]*\] \+\([^ ]*\).*/=\1/p'

This gets all packages. I had edited the script before and couldn't figure out why it was missing every package that portage wanted to downgrade. Didn't take long to figure it out.