This is an old revision of the document!
Table of Contents
Important Grep Notice
Grep Overview
Grep is used extensively by dCore to crawl through extensions, dependency lists and large database files to import and update SCEs. GNU Grep provides faster performance than the built-in BusyBox version. The recommendation is to ensure GNU Grep is installed and utilized.
Grep Utilization
To confirm that GNU Grep is imported and utilized run which grep:
tc@box:/mnt/sda1/tce$ which grep /bin/grep
If the output is /bb/grep the slower BusyBox version is being used. If the output is /bin/grep the faster GNU Grep is likely being used although it may symlink to /bb/grep, so further confirmation is required. Run sudo find / -name “grep”, the results will confirm /bin/grep is loaded and which SCE(s) it comes from, in this case xorg-intel.sce:
tc@box:~$ sudo find / -name "grep" /bin/grep /bb/grep /tmp/tcloop/xorg-intel/bin/grep
Can also run ls -l /bin | grep grep:
tc@box:/mnt/sda1/tce$ ls -l /bin | grep grep lrwxrwxrwx 1 root root 6 Jun 5 16:45 bzegrep -> bzgrep lrwxrwxrwx 1 root root 6 Jun 5 16:45 bzfgrep -> bzgrep lrwxrwxrwx 1 root root 27 Jun 5 16:45 bzgrep -> /tmp/tcloop/lxde/bin/bzgrep lrwxrwxrwx 1 root root 29 Jun 5 16:45 egrep -> /tmp/tcloop/xorg-nv/bin/egrep lrwxrwxrwx 1 root root 29 Jun 5 16:45 fgrep -> /tmp/tcloop/xorg-nv/bin/fgrep lrwxrwxrwx 1 root root 28 Jun 5 16:45 grep -> /tmp/tcloop/xorg-nv/bin/grep lrwxrwxrwx 1 root root 27 Jun 5 16:45 zegrep -> /tmp/tcloop/lxde/bin/zegrep lrwxrwxrwx 1 root root 27 Jun 5 16:45 zfgrep -> /tmp/tcloop/lxde/bin/zfgrep lrwxrwxrwx 1 root root 26 Jun 5 16:45 zgrep -> /tmp/tcloop/lxde/bin/zgrep
In this example grep is symlinked ('l' in lrwxrwxrwx) with /tmp/tcloop/xorg-nv/bin/grep (not /bb/grep):
lrwxrwxrwx 1 root root 28 Jun 5 16:45 grep -> /tmp/tcloop/xorg-nv/bin/grep
Last run echo $PATH to confirm the /bin pathway is prioritized before /bb:
tc@box:/mnt/sda1/tce$ echo $PATH /home/tc/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/bb:/etc/sysconfig/tcedir/ondemand
Import GNU Grep
Some SCEs include GNU Grep, though it is best to confirm using the steps outlined above. For example, xorg-* SCEs appear to include GNU Grep but the Xvesa SCE does not. Users running Xvesa graphics or no graphics may, therefore, not be utilizing the faster Grep. If the SCE that provides this faster Grep is always listed in sceboot.lst then there is no need for a separate import, otherwise import the 'grep' package from the Debian or Ubuntu repositories to load at boot:
sce-import -b grep
GNU Grep Performance
To confirm whether this Grep hassle is worthwhile, an 11 MB mupdf.sce (PDF reader) update check was completed as a case study. This is a moderately sized extension not imported with advanced techniques, such as a dependency import. On slow hardware /bb/grep took 1min:27sec to complete an update check versus 0min:37sec using /bin/grep.
