| === IKRAM_ is now known as IKRAM | ||
| === drkokandy_ is now known as drkokandy | ||
| Blue_ | Hello! | 19:28 |
|---|---|---|
| penguin42 | Hey | 19:30 |
| Blue_ | I am on Ubuntu, I found out that on C shell, the command, source script arg, takes the arg as an empty string. This error does not occur in Linux Red Hat. Is the error documented in the Ubuntu website? | 19:31 |
| * penguin42 hasn't done C shell for about 20 years :-) | 19:32 | |
| penguin42 | can you give me the exact line you typed and what it says? | 19:32 |
| Blue_ | First, at the prompt, I type the command, csh, to get to the C shell. Second, I execute the command, source abc.csh abc and the output: The first parameter is . In the abc.csh file, it has two statements. First statement:#/bin/csh and the second statement:echo The first parameter is $1 | 19:43 |
| Blue_ | I also type the command: chmod 777 abc.csh after creating the file abc.csh | 19:45 |
| penguin42 | hang on, that first line should be #!/bin/csh | 19:45 |
| penguin42 | the ! is important | 19:45 |
| Blue_ | Sorry, yes, it was #!/bin/csh | 19:46 |
| Blue_ | I mis-typed it. | 19:46 |
| penguin42 | no problem | 19:46 |
| penguin42 | OK, so what happens with that script? | 19:47 |
| Blue_ | After I create the file abc.csh, I run the command chmod 777 abc.csh. Then, I ran the command, source abc.csh abc. The output should be The first parameter is abc. However, the actual output is The first parameter is. | 19:49 |
| Blue_ | After I created the file abc.csh, I ran the command chmod 777 abc.csh. Then, I ran the command, source abc.csh abc. The output should be The first parameter is abc. However, the actual output was: The first parameter is | 19:50 |
| penguin42 | ok, so I've just done that on ubuntu u and it seems to work and shows the parameter, so I'm not sure why it's not working for you; but the other thing is you've not quite got the reason for doing the chmod - you don't need to use chmod if you're going to use source, you only need it if you run it directly | 19:50 |
| Blue_ | Did you do it on Ubuntu 14.04? | 19:52 |
| penguin42 | hmm no, I wonder if I have a .04 around | 19:52 |
| Blue_ | I did it on 13.04 also. | 19:53 |
| * penguin42 looks which VMs he has | 19:54 | |
| penguin42 | ah 14.04 is trusty isn't it? | 19:54 |
| Blue_ | It should. | 19:54 |
| penguin42 | ah, I've got a 14.04 vm here | 19:55 |
| penguin42 | ok, so an observation; on 14.10 it's using tcsh when you ask for csh, on 14.04 it's using bsd-csh | 19:55 |
| Blue_ | https://wiki.ubuntu.com/Releases | 19:55 |
| penguin42 | Blue_: Which shell are you in when you do the source? | 19:56 |
| Blue_ | I ran the command, csh, to go to the C shell. | 19:56 |
| penguin42 | ok | 19:56 |
| penguin42 | Blue_: So yes, this looks like a difference in behaviour between bsd-csh and tcsh | 19:57 |
| Blue_ | It may work on tcsh but it does not work on csh | 19:57 |
| penguin42 | Blue_: Many systems just run tcsh when you ask to run csh | 19:58 |
| penguin42 | Blue_: Do you understand what the 'source' is for and what the chmod is for? | 19:58 |
| Blue_ | Is it for setting the environment on the current shell? | 20:00 |
| penguin42 | no | 20:01 |
| Blue_ | Okay, what does the 'source' is for? | 20:01 |
| penguin42 | Blue_: 'source' reads the commands from the file you specify as if you had typed them at the command prompt, if you do the chmod and then do ./abc.csh it runs abc.csh in a new shell - it's only for the later case that you need the chmod | 20:01 |
| Blue_ | Okay, thanks! | 20:03 |
| penguin42 | Blue_: now if you do the ./abc.csh that works on both bsd-csh and tcsh | 20:03 |
| Blue_ | Okay, thanks! | 20:04 |
| penguin42 | Blue_: The command you run with csh goes through a chooser that picks what to run, you can change it with update-alternatives, so if you install tcsh you can make csh run that | 20:04 |
| Blue_ | If I do not have tcsh installed, I ran the command, source abc.csh abc. I do not see the output as The first parameter is abc | 20:07 |
| Blue_ | If I do not have tcsh installed, I ran the command, source abc.csh abc. I do not see the output as: The first parameter is abc. | 20:08 |
| penguin42 | right, it's just a difference in the behaviour of tcsh and bsd-csh | 20:08 |
| penguin42 | both work if you do ./abc.csh hello instead of using source | 20:09 |
| Blue_ | Is the bug filed in Ubuntu? | 20:11 |
| penguin42 | I don't think it's a bug | 20:11 |
| penguin42 | it's just a difference between bsd-csh and tcsh | 20:11 |
| penguin42 | Blue_: Passing parameters through source is not that common, actually using source isn't that common | 20:13 |
| Blue_ | If I go to a Linux Red Hat and run the command, csh, Then run the command, source abc.csh abc. I can see the output as: The first parameter is abc. | 20:13 |
| penguin42 | Blue_: Whether it's a bug in bsd-csh you'd really want to take up with the bsd-csh guys, because I'm not sure it's defined | 20:13 |
| penguin42 | Blue_: So what makes you think it's a bug in the csh ubuntu uses? | 20:14 |
| penguin42 | Blue_: What is the right definition of the csh behaviour of source? | 20:14 |
| hggdh | well, source (or "." in bash) is not THAT uncommon. What is uncommon is passing parameter to it | 20:14 |
| penguin42 | right | 20:15 |
| * penguin42 isn't sure if csh is covered by posix or not or if there is any fixed definition of it | 20:15 | |
| hggdh | yeah, neither am I | 20:15 |
| Blue_ | If I go to a Ubuntu and run the command, csh, Then run the command, source abc.csh abc. I should see the output as: The first parameter is abc. The behavior should be the same as in the Linux Red Hat. Am I correct? | 20:15 |
| hggdh | Blue_: penguin42 has gone thru already. Summary is it depends: is csh and tcsh are identical, version differences, etc | 20:16 |
| penguin42 | Blue_: http://www.kitebird.com/csh-tcsh-book/csh.pdf doesn't specify parameters to source (page 14) | 20:16 |
| penguin42 | sorry, 15 | 20:17 |
| penguin42 | Blue_: No, you're wrong | 20:17 |
| penguin42 | Blue_: You're failing to understand 1) The difference between source and running a shell script directly 2) What defines the behaviour of source 3) That there are differences between different implementations | 20:17 |
| penguin42 | Blue_: Compare that document above with the tcsh manpage http://www.kitebird.com/csh-tcsh-book/tcsh.pdf page 34 that lists it's source takes args | 20:18 |
| hggdh | and, now, one should point out that tcsh and csh are *not* the same thing | 20:19 |
| Blue_ | I am sorry. I do not understand why there are different behaviors between Red Hat Linux and Ubuntu. | 20:21 |
| penguin42 | Blue_: Because there are multiple implementations of csh, they have subtle different behaviours | 20:22 |
| penguin42 | Blue_: The feature you're using is one of these differences because you're not using the feature you think you are | 20:23 |
| penguin42 | Blue_: Go and read those two documents I pasted which define the source command in two different csh versions | 20:24 |
| Blue_ | I apologize to repeat my question because I still do not quite understand. Is Red Hat Linux csh is the same as tcsh? I did the command, ps -p $$, in the Red Hat Linux. I saw CMD=csh. | 20:35 |
| Blue_ | Is Ubuntu csh is not the same as tcsh? Is that the reason I am seeing different behaviors between Ubuntu and Red Hat Linux? | 20:36 |
| penguin42 | correct, the csh on 14.04 is bsd-csh not tcsh | 20:38 |
| penguin42 | (by default if you just install csh, you can install tcsh if you want) | 20:39 |
| hggdh | and, usually, tcsh will set itself as csh | 20:44 |
| Blue_ | I googled bsd-csh and was unable to find its definition. What are the difference between bsd-csh and csh? Is bsd-csh the same as csh? | 20:44 |
| penguin42 | see the manpages I posted | 20:46 |
| hggdh | bsd csh was also known as Berkeley csh. 'bsd' means "Berkeley Software Distribution" | 20:46 |
| penguin42 | right, bsd was one of the early unix systems | 20:46 |
| penguin42 | I think bsd systems had the original csh but not 100% sure on that | 20:47 |
| hggdh | and we owe a LOT to the folks at UC-Berkeley | 20:47 |
| hggdh | not sure either. I do not remember if csh started at Bell Labs, and bsd-csh was a variant | 20:49 |
| hggdh | ah, wikipedia to the rescue -- csh was authored by Bill Joy, while he was at UC-B | 20:51 |
| penguin42 | yeh that rings a bell | 20:51 |
| hggdh | so bsd-csh and csh are the same | 20:52 |
| Blue_ | If Red Hat Linux csh is the same as tcsh? Why did I see CMD=csh after running the command, ps -p $$, in the Red Hat Linux? <hggdh> said, tcsh will set itself as csh. Is it the answer? | 20:54 |
| Blue_ | If Red Hat Linux csh is not the same as tcsh, why did I see CMD=csh after running the command, ps -p $$, in the Red Hat Linux? <hggdh> said, tcsh will set itself as csh. Is it the answer? | 20:55 |
| hggdh | Blue_: because usually tcsh will install itself as csh (it *is* a C shell, after all). But I do not know if RH uses tcsh or csh. If I were to do it, I would go tcsh | 20:55 |
| hggdh | Blue_: so yes, this is the answer | 20:55 |
| hggdh | probably :-) | 20:56 |
| hggdh | Blue_: you probably can find it by 'rpm -q -a | grep csh' on RH system | 20:56 |
| hggdh | if you only see tcsh shown as installed, then there you go | 20:57 |
| Blue_ | Yes, I saw tcsh on the Red Hat Linux machine. I tried the command, rpm -q -a | grep csh, on Ubuntu. I gave the error: rpm:Command not found. | 21:03 |
| Blue_ | Yes, I saw tcsh on the Red Hat Linux machine. I tried the command, rpm -q -a | grep csh, on Ubuntu. It gave the error: rpm:Command not found. | 21:04 |
| Blue_ | May be rpm is a Red Hat command only. | 21:05 |
| Blue_ | rpm is Red Hat specific. | 21:06 |
| hggdh | rpm is available on RH, Fedora, and CentOS, at least | 21:08 |
| hggdh | maybe it is out of your default path | 21:08 |
| hggdh | on Debian (and variants, like Ubuntu) you should use 'dpkg -l \*csh' | 21:10 |
| Blue_ | hggdh++: Thanks! I ran the command, dpkg -l \*csh, on Ubuntu and found Name=ii csh. Description=Shell with C-like syntax | 21:24 |
| Blue_ | hggdh++: Thanks! I ran the command, rpm -q -a | grep csh on Red Hat Linux and found tcsh. | 21:25 |
| Blue_ | The reason why there are different behaviors in Ubuntu and Red Hat Linux is Ubuntu uses Berkeley Software Distribution C shell and Red Hat Linux uses tcsh. Am I correct? | 21:31 |
| sfp | would a member of ubuntu-bugcontrol please nominate bug #1409798 for 14.04 and 14.10? | 22:19 |
| ubot5 | bug 1409798 in dropbear (Debian) "enable hmac-sha2-256, hmac-sha2-512 MAC algorithms" [Unknown,New] https://launchpad.net/bugs/1409798 | 22:19 |
| hggdh | Blue_: correct | 23:47 |
| hggdh | sfp: Trusty and Utopic have been targeted | 23:50 |
| teward | hggdh: boo you stole it from me | 23:51 |
| * teward glares | 23:51 | |
| teward | nah i kid :) | 23:51 |
| hggdh | teward: heh | 23:52 |
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