Top new questions this week:

Can you legally sell modified versions of Linux distros?

Suppose somebody downloaded a Linux distro, like Ubuntu. Suppose further modify one piece of it, say the Window Manager. Would it be perfectly legal for them to sell copies of this slightly modified ...

/ licenses

asked by George 29 votes answered by hvd 52 votes

How to process a multi column text file to get another multi column text file?

I have a text file: a aa aaa b bb bbb c cc ccc d dd ddd e ee eee f ff fff g gg ggg h hh hhh i ii iii j jj jjj How can I process it and get a 2 ...

/ text-processing / awk

asked by Ogrish Man 12 votes answered by Thor 14 votes

Execution cycle of sed s/REGEXP/REPLACEMENT/g

Why does echo ,,, |sed s':\(,\)\(,\):\1*\2:'g yield ",*,," rather than ",*,*,"? In other words: why, despite the "g" flag, does sed not insert '*' between one pair of commas?

/ sed / regular-expression

asked by user3143179 10 votes answered by heemayl 11 votes

awk condition of true and false

I came across that if we use awk 0 inputfile, it will not print anything cause 0 means false of the condition. If we use awk 1 inputfile, it will print everything as 1 means true for each line awk ...

/ awk / gawk

asked by sylye 7 votes answered by Stéphane Chazelas 10 votes

What does "test $2 &&" mean in this bash script?

I'm looking at a bash script with the following code: #!/bin/sh set -e # Exit if any command fails # If multiple args given run this script once for each arg test $2 && { for arg in $@ ...

/ bash / scripting

asked by mbigras 7 votes answered by Stéphane Chazelas 13 votes

Find all absolute links in a directory tree

How do I (recursively) detect all symlinks in a directory that identify their target in an absolute as opposed to in a relative way? Since these links are very likely to break when an entire ...

/ symlink

asked by Marcus Junius Brutus 6 votes answered by Stephen Kitt 9 votes

How to get block device name from partition device name?

I'm looking for a portable way to obtain parent block device name (e.g. /dev/sda) given the partition device name (e.g. /dev/sda1). I know I could just drop the last character, but that wouldn't work ...

/ shell-script / partition / block-device

asked by Dmitry Grigoryev 6 votes answered by don_crissti 7 votes

Greatest hits from previous weeks:

How to switch between users on one terminal?

I'd like to log in as a different user without logging out of the current one (on the same terminal). How do I do that?

/ login / users

asked by Tshepang 231 votes answered by Pratt 263 votes

How to forward X over SSH from Ubuntu machine?

I have a machine running Ubuntu which I SSH to from my Fedora 14 machine. I want to forward X from the Ubuntu machine back to Fedora so I can run graphical programs remotely. Both machines are on a ...

/ ssh / xorg / xforwarding

asked by Mr. Shickadance 176 votes answered by Gilles 200 votes

Can you answer these?

Why is a variable in a `require`d module not always available?

I've got three module manifests in separate files (stripped down to bare essentials): class users { $user = 'foo' user { $user: ensure => present; } } class dvcs_cli { require users ...

/ puppet

asked by l0b0 2 votes

Git Server with several repos

I'm setting up a git server, and there will be three different groups working on different projects iOS, WebDevel, Android. I need to do it in a secure/safe way. Meanwhile, I don't want iOS ...

/ ssh / security / git / repository

asked by ParsaX 2 votes

How to render geojson locally

I have some visualizations which consists of data in the GeoJSON format. I would like to render the features to a png file. There are some sites which provide this functionality. I have for example ...

/ utilities / images / json

asked by hfhc2 2 votes