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| Time Nick Message | ||
| 00:09 melodie this topic has been posted at the LinuxVillage forum today: If you're a freedom lover, here's something you should be aware of - http://beta.linuxvillage.net/index.php/topic,353.0.html | ||
| 00:10 melodie the article itself is scary | ||
| 00:10 melodie methinks... | ||
| 00:14 pdurbin something about https://en.wikipedia.org/wiki/Bilderberg_Group ? | ||
| 00:14 pdurbin which I've never heard of | ||
| 00:15 melodie pdurbin I have heard of before | ||
| 00:15 melodie ues, there is something about them at the page you point to | ||
| 00:17 semiosis crazy conspiracy theories | ||
| 00:18 melodie semiosis perhaps, or not | ||
| 00:18 semiosis lol | ||
| 00:18 melodie pdurbin do you easily read long pages at the screen ? | ||
| 19:20 melodie hi | ||
| 19:21 melodie is someone around? | ||
| 19:22 larsks What's up? | ||
| 19:22 melodie hi larsks | ||
| 19:23 melodie someone asking a question related to bash in #linuxchix at irc.linuxchix.org : I am waiting to see if she pops up here | ||
| 19:23 larsks Okee dokey. Happy to help out if I can. | ||
| 19:24 melodie nice! | ||
| 19:30 melodie hi soulshake ! | ||
| 19:30 soulshake o/ | ||
| 19:30 melodie larsks here is the question which was asked | ||
| 19:30 melodie <aj> can somebody enlighten me as to the purpose of this construct in a sh script? if [ "o$2" != 'o' ]; then | ||
| 19:30 melodie <aj> what is with the 'o' in that context? | ||
| 19:30 melodie <aj> (trying to read somebody else's code) | ||
| 19:30 melodie <aj> it looks to me like they were trying to test if $2 is empty, in a weird roundabout way | ||
| 19:30 melodie larsks what do you think? | ||
| 19:37 larsks I believe in old versions of the Bourne shell, if "$2" evaluated to an empty string it could cause problems. So putting that "o" there guarantees that the string will never be empty. | ||
| 19:37 larsks You see that, for example, in GNU autoconf scripts (which try to be as portable as possible). | ||
| 19:38 larsks Here: http://stackoverflow.com/questions/6852612/bash-test-for-empty-string-with-x | ||
| 19:40 soulshake interesting! thanks | ||
| 19:40 melodie this is very interesting | ||
| 19:41 melodie larsks what about recent versions of the Bourne shell ? | ||
| 19:41 melodie no problem with $2 produces an empty string? | ||
| 19:43 larsks If you read the answer on stackoverflow, you'll note it's not just empty strings but also variables that start with "-" (or possibly other characters). With bash, at least, this isn't a problem: given $foo="-gt", I can run '[ "$foo" ]' without errors. | ||
| 19:43 larsks Don't know about other shells. | ||
| 19:43 larsks I think in general if you quote your variable expansion ("$2") you're okay. | ||
| 19:43 larsks Bash and other modern shells also have the '[[ ... ]]' operator which has slightly saner semantics than the traditional Bourne shell test. | ||
| 19:52 melodie what is the difference between "traditional Bourne shell" and "BASH" which means "Bourne Again SHell" as I was told? | ||
| 19:52 melodie when is the frontier? | ||
| 19:52 melodie or version number? Or is it a complete rewrite? | ||
| 19:53 melodie as far as you know... | ||
| 19:53 melodie me newbie forever :) | ||
| 19:54 larsks Well, Bash supports most traditional Bourne shell syntax plus a number of its own extensions. | ||
| 19:55 melodie ok, thanks for the explanation | ||
| 19:55 larsks "Traditional Bourne shell" means something that complies with (I think) the POSIX requires for /bin/sh. You don't see them too much in practice...but for example, some Debian or Ubuntu may use "dash", so bash extensions aren't available in /bin/sh. | ||
| 19:55 larsks This is why you should always use /bin/bash if you expect to use bash extensions. | ||
| 19:56 melodie instead of ? of /bin/sh perhaps ? | ||
| 19:57 melodie yes, I just reread what you just said | ||
| 19:57 melodie now i understand the difference | ||
| 20:08 ben_e the BSDs all use some stripped down version of /bin/sh that is neither bash-derived nor dash | ||
| 20:08 ben_e http://svnweb.freebsd.org/base/releng/9.1/bin/sh/ <- e.g. | ||
| 20:37 semiosis just did a little inspecting of the new google play music all access stream & found 320k MP3 inside | ||
| 20:37 semiosis not too shabby | ||
| 21:11 ben_e beer o'clock | ||
| 21:11 pdurbin soccer practice o'clock |