Developp Bash script without worrying

I have often used bash to write shell script. In most cases, you have to hurry up and you don't go further into ... Here is two tips that could help you.

Developp without worrying

To developp bash script, it's better to use the following :

#!/bin/bash
set -euo pipefail
IFS=$'\n\t'

With theses paramters, you will be able to detect silent errors, un intialize variables and so on...
See that good link for more details : http://redsymbol.net/articles/unofficial-bash-strict-mode/

Help in syntax

Here is a cool link to help you in shell syntax : http://www.shellcheck.net/

app-textrarian compilation failed

Last week, I had problem with app-textrarian compilation.
So I ask about this on funtoo forum and a work around was given to me.
If you change the LINGUAS to EN, it compiles.Thanks to Oleg Vinichenko.

My posts :
http://forums.funtoo.org/index.php?/topic/161-app-textrarian-081-r2-failed/
https://bugs.funtoo.org/browse/FL-1497

emerge: there are no ebuilds to satisfy

I had the following message when I executed emerge -p world :

emerge: there are no ebuilds to satisfy "sys-kernel/gentoo-sources:3.10.32". (dependency required by "@selected" [set]) (dependency required by "@world" [argument]) 
emerge: there are no ebuilds to satisfy "sys-kernel/gentoo-sources:3.12.13". (dependency required by "@selected" [set]) (dependency required by "@world" [argument])

The solution is to remove ebuild from world file :

emerge --deselect sys-kernel/gentoo-sources:3.10.32

Thanks to mackal for the solution
See the post message on Gentoo forum : https://forums.gentoo.org/viewtopic-t-998826-highlight-.html

dev-lang/perl conflict

I started to look at Funto project ( an other version of Gentoo) and I met a problem during update :


WARNING: One or more updates have been skipped due to a dependency conflict:

dev-lang/perl:0

  (dev-lang/perl-5.18.2-r1::gentoo, ebuild scheduled for merge) conflicts with
    =dev-lang/perl-5.16* required by (virtual/perl-Perl-OSType-1.2.0-r1::gentoo, installed)


To solve this problem, I ran the following commands :

emerge -1auD $(qlist -IC 'virtual/perl-*')
perl-cleaner --all

See also forum Gentoo



Note :

When I executed emerge command, it appears a problem with the following package : app-text/rarian. I will look at this problem later.

 * Messages for package app-text/rarian-0.8.1-r2:

 * ERROR: app-text/rarian-0.8.1-r2 failed (compile phase):
 *   emake failed
 *
 * If you need support, post the output of `emerge --info '=app-text/rarian-0.8.1-r2'`,
 * the complete build log and the output of `emerge -pqv '=app-text/rarian-0.8.1-r2'`.
 * The complete build log is located at '/var/tmp/portage/app-text/rarian-0.8.1-r2/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/app-text/rarian-0.8.1-r2/temp/environment'.
 * Working directory: '/var/tmp/portage/app-text/rarian-0.8.1-r2/work/rarian-0.8.1'
 * S: '/var/tmp/portage/app-text/rarian-0.8.1-r2/work/rarian-0.8.1'

 * Regenerating GNU info directory index...
 * Processed 109 info files.

Difficult back from holiday with systemd

Back from holiday, I decided to update my Gento and I had som problems during update
with systemd.
I found the solution on Gentoo forum :

sys-apps/systemd contains udev and, then, you can safely let sys-fs/udev be removed as systemd will be the provider for virtual/udev.
sys-apps/systemd and sys-apps/dbus have a circular dependency which necessitates a 2-stage installation.
Install sys-apps/dbus with USE="-systemd". This is probably already done if you have a working desktop environment.
Enable the systemd USE flag globally (make.conf) and install sys-apps/systemd. This may also be accomplished by a world update. The consolekit use flag should also be disabled to prevent conflicts with the systemd-logind service. You can also switch to a systemd subprofile to use saner USE flags defaults not needing to change make.conf:

Thanks to eyoung100  : http://forums.gentoo.org/viewtopic-t-977642-start-0.html

PrintScreen on KDE

If like me, you installed KDE by hand and you don't have screen capture, it is certainly that you don't have the ksnapshot installed.
So you have to run the following command :


emerge ksnapshot






Some comment about KSnapshot. It has interesting feature like :

• Snapshot delay for capture drop down menu.
• You can choose to add or not the mouse cursor.
• You can send your snapshot to an other software like for example Gimp.
• ALT Gr + printscreen is a shortcut to take only a window capture.

See also: http://userbase.kde.org/KSnapshot

Shell script debugger online

ShellCheck is a online tool to debug script shell.
You only have to paste your shell script and clic on a button to see if there is error and help you to find it !
So a great tool to have in this pocket !

More information : http://www.shellcheck.net/