23.10.09

pbcopy and pbpaste for Linux

Tags: , , , , , , — Jeff @ 14:43

Mac OS X has the useful commands pbcopy and pbpaste. pbcopy reads the contents of standard input into the clipboard; pbpaste writes the contents of the clipboard to standard output. These commands aren’t part of the standard set of commands on Linux, but they’re easily added. Simply install the XSel program via a package management system or directly from source, then add these lines to ~/.bashrc. Voilà! Easy commandline access to the clipboard.

alias pbcopy='xsel --clipboard --input'
alias pbpaste='xsel --clipboard --output'

16.10.09

Working on the JS engine, redux

In a continuation of a topic started by mrbkap, I present you this gem of a gdb command I needed to use today:

cond 8 \
  (*$9 && \
   ((*$9)->id&7) == 4 && \
   (*(jschar**)((uintptr_t) (*$9)->id + 4))[0] == 'o' && \
   (*(jschar**)((uintptr_t) (*$9)->id + 4))[1] == 'f' && \
   (*(jschar**)((uintptr_t) (*$9)->id + 4))[2] == 'f')

For minimal background, breakpoint 8 was the result of watch *$9, and of course $9 = (JSScopeProperty **) 0x7ffff2f08038.

By the way, did you know the gdb command line supports line continuations? I didn’t, before I had to think about how the above command would display without any. :-) This is the above command as I originally wrote it:

cond 8 (*$9 && ((*$9)->id&7) == 4 && (*(jschar**)((uintptr_t) (*$9)->id + 4))[0] == 'o' && (*(jschar**)((uintptr_t) (*$9)->id + 4))[1] == 'f' && (*(jschar**)((uintptr_t) (*$9)->id + 4))[2] == 'f')

15.10.09

My distro can beat up your distro’s honor student. Or something like that. (Or: setting up ccache-powered Firefox builds in Fedora)

Tags: , , , , , , — Jeff @ 22:23

dholbert makes a recent post (well, recent only in planet.mozilla.org‘s little mind, no idea why a post from September 2008 is being displayed as new!) discussing how to build Firefox with ccache on Ubuntu, saving compilation time on close to null-program rebuilds. Cool beans. However:

If you’re on Fedora 11 (conceivably earlier too, I regretfully haven’t regularly used Fedora since Fedora 6, until recently), the basic developer tools package combo includes ccache, and caching Just Works in Firefox builds with no extra work needed at all.

[jwalden@the-great-waldo-search dbg]$ \
> ls -la `which g++` `which c++` `which gcc` /usr/bin/ccache
-rwxr-xr-x. 1 root root 43584 2009-02-23 23:42 /usr/bin/ccache
lrwxrwxrwx. 1 root root    16 2009-10-02 21:29 /usr/lib64/ccache/c++ -> ../../bin/ccache
lrwxrwxrwx. 1 root root    16 2009-10-02 21:29 /usr/lib64/ccache/g++ -> ../../bin/ccache
lrwxrwxrwx. 1 root root    16 2009-10-02 21:29 /usr/lib64/ccache/gcc -> ../../bin/ccache
[jwalden@the-great-waldo-search dbg]$ du -hs ~/.ccache
883M	/home/jwalden/.ccache

Anyway, use whichever distro you want, with ccache or without, whatever satisfies your preferences and utility curve. (The semi-troll title is completely gratuitous, but my sense of humor mandated I use it. :-) ) As for me: I am an absolute sucker for convenience. I’ve known of ccache for years and never used it before due to the activation energy needed to do so; had using ccache required equivalent effort in Fedora I strongly doubt I’d ever have used it. Score one for making the right choice for the user rather than requiring him to make it himself.