/dev/chat

strugee

12:51 AM

@derobert angry Linus wanted you to know: he's on your side. casibien.files.wordpress.com/2012/10/22814678.jpg

slm

1:01 AM

@strugee - I love that angry linus

strugee

@slm I know, right? he's on GNOME Memes, too: gnomememes.tumblr.com/post/25510925047 and gnomememes.tumblr.com/post/25351417013/…

especially relevant since you just upgraded

Gilles

0

A: Count the number of characters in all files

Here's a way to do this in a single shell command. <foo awk 'FILENAME=$0{while(getline<FILENAME>OUTPUT&&match($0,"$"))RSTOP-=RSTART}END{print-RSTOP}' This may not be the least awkward way to do it. Be sure to tell me what your teacher thinks of it.

slm

@Gilles - now you're doing ppl's homework 8-)

strugee

heh. "may not be the least awkward"

although you did forget to assign it to $count

Gilles

@strugee ah, dammit

do you think it counts if I assign it in awk?

strugee

1:15 AM

probably

Gilles

there, done

unfortunately, the way I did it may make him think it didn't work

but I do assign it to the shell variable count, and it does work if you run it right

derobert

@slm Odd, why did no one vote to close?

slm

0

A: Count the number of characters in all files

Since apparently we're answering this quesiton now. Sample data $ ls -1 afile1 afile2 afile3 filelist.txt $ cat afile{1..3} blah blah blah Example $ cnt=0; for i in $(< filelist.txt);do \ let cnt="cnt+$(wc -c $i | cut -d" " -f1)";done; echo $cnt 15 In it's expanded form: $ cnt=0; $ fo...

I did one too

derobert

@slm you failed, that's not a single statement

strugee

I wonder why he tagged it cat. reminds me of the useless uses of cat award

derobert

1:29 AM

Yeah. Maybe that's the list of Unix commands OP knows?

strugee

pipe isn't a command

otherwise I would agree with you

derobert

I bet the actual assignment was to read man wc and see --files0-from=F ...

If you all want to do someone's homework, there is a sorting one on codegolf!

236

Q: I need a program where the user inputs an array of doubles and the program outputs the array sorted

Note: This question was severely edited since I first posted it here. The rules were moved to here, read them before posting any answer to understand the purpose of this. This was the first question created in the code-trolling category. Imagine a lazy user on Stack Overflow asks this question: ...

strugee

I've never actually bothered to read any of man wc except for the top where it specifies the -l, -c and -w switches...

slm

@derobert - what constitutes a statement? It's on one line, that's a statement in my book

strugee

@slm I would agree but yours wasn't on one line. I mean, it could easily be put on one line, but I think @derobert was nitpicking

derobert

1:40 AM

@slm Nah, semicolons separate statements (most of the time). A statement is a formal part of a language's grammar... yes, this is very nitpicky.

strugee

do people see a need for a shell-startup tag? I'm asking a question that might use it right now, but I'm not sure if it's useful

derobert

I'm not sure what you'd use it for...

slm

I split it on one line for readability on the site. I hate when code shows up and I have to scroll over to the right

Wow skeet is up to 635k

4

Q: Why does the wc utility generate multiple lines with "total"?

I am using the wc utility in a shell script that I run from Cygwin, and I noticed that there is more than one line with "total" in its output. The following function is used to count the number of lines in my source files: count_curdir_src() { find . '(' -name '*.vb' -o -name '*.cs' ')' \ ...

shell cygwin

strugee

@derobert e.g. .bash_profile, .profile, .zshrc, etc.

derobert

@strugee Is there an expert in that? Probably not. There is an expert in bash (and zsh, and ksh, and even csh), surely, but in shell-startup? I don't know...

strugee

1:43 AM

/me shrugs

that's why I asked, since it seems like it might not be used very much

derobert

I wouldn't bother :-P

strugee

ok.

switching topics, just out of curiosity, has anyone here ever played with Plan 9? (mostly asking since I'm setting up a space for a Plan 9 server right now)

derobert

not I

Gilles

@derobert or a command substitution, which is the way I'd do it

I posted that question and a variant of the answer in the place where it belongs:

0

Q: Count the total number of characters from a list of files

The challenge: A file foo contains a list of filenames. Devise a single statement that stores in a variable count the total character count of the contents of these files. (From crisron's teacher via http://unix.stackexchange.com/questions/107336/count-the-number-of-characters-in-all-files...

code-trolling text

derobert

Now I'm tempted to answer it!

I'm not sure though, it's possible a good answer would require FUSE. Or maybe direct access to the underlying filesystem.

For efficiency, of course.

strugee

1:49 AM

so am I, with a solution involving curl, make, gcc and friends

Gilles

@slm I left a confusing comment on your answer. <evil laughter>

derobert

curl? This should be interesting!

Actually. Hmm. I know!

EVIL GRIN

strugee

@derobert yeah... it's not all that clever once you figure it out

derobert

@strugee no, I'm referring to what I just thought of. I need to grab a name dictionary, first...

strugee

ah

I think I spend to much time at the terminal/on Stack Exchange, because I just opened an instruction sheet to assemble a table for a P9 server

and it said "assembly instructions" at the bottom of the front page and my mind immediately went to x86 assembly

slm

2:01 AM

@derobert - here's your --files0-from method

1

A: Count the number of characters in all files

Since apparently we're answering this quesiton now. Sample data $ ls -1 afile1 afile2 afile3 filelist.txt $ cat afile{1..3} blah blah blah Example $ cnt=0; for i in $(< filelist.txt);do \ let cnt="cnt+$(wc -c $i | cut -d' ' -f1)";done; echo $cnt 15 In it's expanded form: $ cnt=0; $ fo...

@Gilles - I fixed the stray quote, i had double quotes from a cut nested inside the let's double quotes

derobert

Working on my trolling answer.

Braiam

@derobert you taking my lines (that I took from someone else)?

Gilles

@slm oh, there really was a stray quote? I hadn't noticed it!

derobert

I shall nest map repeatedly!

slm

@Gilles - I have to agree these are actually not bad Q's for us to have on the site, but I feel we're sending the wrong msg by helping these ppl

Gilles

2:05 AM

the “stray quote” I meant was an it's that should have been its

@slm if he submits my answer without trying to understand it, he's going to get a lesson on doing his own homework

if he works to understand my answer, he's going to learn a lot about awk

slm

@Gilles - i see the quote now, fixed.

i'm not sure if you can have nested quotes inside of a let

the code worked before

Gilles

@slm you can

slm

ah so it was legal then, I changed it to single quotes any way for cut

Gilles

rather: the quote was inside a $(…), and you can use quotes normally inside $(…)

@slm yes, but it worked either way

slm

ah yes you'd be correct completely missed i was inside the $()

Gilles

2:16 AM

@slm you aren't assigning to count

can you throw something in so that it works if the variable is called cnt, but not if it's called count?

use count as the loop variable, for example

slm

2:33 AM

@Gilles in the golf example or on U&L?

Gilles

@slm at least in the PCG example, where the point is to make the code work (at least on some input) but be brittle or unmaintainable in some way

your code is almost decent

slm

@Gilles - do you just want me to change the $i to $count in the loop?

I've never seen the code-trolling tag before

Gilles

@slm it's new

slm

so just change the index?

i'm drawing a blank on how you want me to make it brittle

derobert

				local $p = $p; # this line is important! do not delete.

... random line from my answer, still in progress :-P

slm

2:38 AM

oh just change the scope of $cnt?

Gilles

@slm change the loop variable, so if he just renames cnt to count he'll have a clash

or whatever you want to make it a more brittle

@slm you forgot to change one occurrence, it only works for a single file. Or was that deliberate? (Answers that work for sample data but not in general are allowed, even somewhat encouraged)

slm

that was intentional

that was how i was obfuscating the original answer over here

i still don't understand what you want me to change

it's unantural to make it terse

cnt=0; for i in $(< filelist.txt);do let count="count+$(wc -c $i | cut -d' ' -f1)";done;

strugee

i think he wants you to change i's name

slm

i changed cnt to count, i thought there was more to it though

Also why did someone dv your Q there?

someone commented about my code not being very trolling, i think i'm missing the point of something here, i read the code-trolling tag

Gilles

@slm I'm new to that tag as well, maybe we're missing some convention

did you read the tag wiki?

you should probably explain more what the trolling aspect is

slm

2:55 AM

@Gilles - I made the variables more brittle as you suggested, so now it sometimes works and doesn't display the value, I also neutered the --files0-from example so that you have to know ho to extract the value using awk etc. yourself

@Gilles - this site seems like it's gonna have a hard time getting out of beta

Gilles

@slm yes, I wouldn't be surprised if it remained in beta indefinitely

I have a close vote on the question because I didn't provide an objective winning criterion

I guess it'll be score by default (that's allowed)

derobert

0

A: Count the total number of characters from a list of files

I believe the below Perl solution fits the requirements. In order to use it, you'll need to prepare several data files: first-names: should contain a list of possible first names, separated by newlines. last-names: same, but for last names. titles: a list of titles (Mr., Mrs., Lord, etc.). Mak...

slm

ah

derobert

There, my answer!

slm

@derobert - took you long enough 8-)

derobert

3:00 AM

take a look at it, and I think you'll understand why...

slm

wow you really did it with map, i thought you were joking

Gilles

LOL at “characters”!

derobert

who needs loops, when you have map? :-P

@Gilles yeah, that was my EVIL GRIN when I realized I could use that meaning.

I wonder how big the first-names, last-names, and titles files can be, before the regex compiler dies

slm

@deroberts - i can't believe you made this abomination

Gilles

did you try it on real input, like a Shakespeare play?

derobert

3:04 AM

@Gilles hell no!

anthony@Watt:/tmp/cc$ cat f1
Hello, John Smith!

Welcome to Washington.

Smith, John left.
anthony@Watt:/tmp/cc$ cat f2
Lord Bob Smith ate a cat. Mr. Smith was full.

@Gilles next you'll want me to try it with a real list of first & last names. I wonder if I have enough RAM...

derobert

3:34 AM

I've made some improvements, I'm tempted to combine the sum into the counting code (in the obvious way). That'll still be one statement, I think. Or it could be, as I could not use block map there.

But then of course it'd lose the joke about "the statement you're looking for" being a trivial and obvious one

davidkennedy85

5:59 PM

Anybody home? I need some help with SSH master connection

Gilles

6:13 PM

@davidkennedy85 don't ask to ask, go ahead and ask

davidkennedy85

Okay

Well I'm trying to do this from an expect script

So the first thing I do is spawn ssh -N -M root@192.168.1.1

Then I have my expect {} block to send the password

But at that point I'm kinda confused about what to do next

For instance, the next command that I run will run on the remote server or local?

And if it's local do I need to spawn scp or just scp?

Gilles

as long as you're interacting with the ssh command (with send), you're executing remote commands

if you run other commands with spawn, they're local commands

davidkennedy85

So in an expect script I can never run just straight up scp command?

It always has to be prefixed with either spawn or send

Gilles

you can use any tcl command

expect is a tcl library (well, extension)

davidkennedy85

Ono I don't know what tcl is :(

Gilles

6:18 PM

Tcl

Tcl (originally from Tool Command Language, but conventionally spelled "Tcl" rather than "TCL"; pronounced as "" or "tee-see-ell") is a scripting language created by John Ousterhout. Originally "born out of frustration", according to the author, with programmers devising their own languages intended to be embedded into applications, Tcl gained acceptance on its own. It is commonly used for rapid prototyping, scripted applications, GUIs and testing. Tcl is used on embedded systems platforms, both in its full form and in several other small-footprint versions. The combination of Tcl and ...

davidkennedy85

In general normal bash commands are not tcl commands though right?

Gilles

If you don't want to learn tcl, write your program in another language and only use expect to launch the ssh master connection and send the password

@davidkennedy85 no, they are different programming languages

davidkennedy85

By write it in another language, you mean call a bash script from my expect script?

Gilles

no, the other way round

davidkennedy85

ah

That sounds like a good approach

Thanks for your tips I will probably be back in a bit

slm

6:40 PM

@terdon - I thought this was a novel way to use paste

0

A: how to cut and transpose some line of the file in linux?

Only because I love using paste so much, you can actually do this with paste, though it isn't pretty: Sample data $ seq 100 > data.txt Example $ paste -d " " - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - < data.txt 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 ...

The 2nd example is actually smaller than your perl example 8-)

terdon

@slm hah, I just upvoted that, it was a great paste!

Especially with the loop, very nice!

Happy new year by the way

slm

see the xargs example i just added too

same to you bud

davidkennedy85

7:00 PM

I'm using getopts to set a bunch of variables in my script: $source, $dest, etc.

Is this a good way to check for missing arguments?

${source:?"source not specified"}

${dest:?"dest not specified"} etc.

slm

tcl is a pretty retried programming lang. I've used it extensively for years

davidkennedy85

I mean in bash

I know I can do if [ -z $source ] but the ${param:word} syntax is a little neater, just not sure if I'm doing it right

Nvm I think I probably want to if [ -n $source ] as it checks for empty string

or if [ ! -n $source ] rather

davidkennedy85

7:29 PM

@Gilles would you put the initial ssh connection in the bash script or the expect script?

Gilles

@davidkennedy85 expect, it's the whole reason to use expect at all

davidkennedy85

Sorry I'm having trouble with the workflow

So my bash script calls expect like this: expect -f upload.exp $params

then upload.exp does ssh whatever; expect {}

What was the point of doing the bash script again?

Are all the ssh commands from that point going in bash script or expect script?

I was under the impression the expect script would do only the part that I can't do in bash

Gilles

expect to start the master ssh connection

shell to do everything else

including killing the master connection at the end

davidkennedy85

Wouldn't putting ssh -O exit at the end of the expect script cause the connection to terminate before the rest of the ssh commands in the bash script?

Oh wait

Sorry I read that the wrong way, ssh -O exit goes in bash script

This is like one of the most complicated programs I've ever made

davidkennedy85

7:50 PM

0

Q: bash script calls expect script with master SSH connection madness

I'm trying to write bash script that calls an expect script to establish a master SSH connection to be used for the remaining SSH commands in the bash script. I'm a little worried about running it though because it is really confusing and I'm not sure if I'm doing it right. ~/.ssh/config: Contr...

bash ssh scp ssh-tunneling expect

davidkennedy85

8:11 PM

@Gilles could I bother you to glance at that Q?

I just want to make sure I'm understanding this

davidkennedy85

10:13 PM

Can someone please take a look at that question? I'm stuck trying to figure out why the SSH connection can't authenticate from my script

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