[SOLVED] Putting to much into one line

paliga · 09-14-2010, 04:39 AM

Is there a way to put something like:

ls /some/dir 2>/tmp/.myname_FUNNYPART_$RANDOM,

where FUNNYPART is the output of pwd, where the "/" are switched to "-",

in one line?

thanks in advance!

cherioos...

JohnGraham · 09-14-2010, 05:22 AM

Quote:

Originally Posted by paliga

Is there a way to put something like:

ls /some/dir 2>/tmp/.myname_FUNNYPART_$RANDOM,

where FUNNYPART is the output of pwd, where the "/" are switched to "-",

in one line?

thanks in advance!

cherioos...

You can do it like this:

Code:

ls /some/dir 2>"/tmp/.myname_$(pwd | tr '/' '-')_${RANDOM}"

In this, the code "pwd | tr '/' '-'" gets run first, and whatever it puts onto stdout will get inserted into the command.

(Note: you need {}-style braces to make "${RANDOM}", not "$(RANDOM)")

quanta · 09-14-2010, 05:37 AM

Quote:

Originally Posted by paliga

Is there a way to put something like:

ls /some/dir 2>/tmp/.myname_FUNNYPART_$RANDOM,

where FUNNYPART is the output of pwd, where the "/" are switched to "-",

in one line?

thanks in advance!

cherioos...

You should use:

Code:

$ ls . | tee /tmp/.yourname_$(echo `pwd` | sed 's/\//-/g')

colucix · 09-14-2010, 06:40 AM

No need to invoke external commands in bash:

Code:

2> /tmp/.myname_${PWD//\//-}_$RANDOM

cbh2000 · 09-14-2010, 12:29 PM

Off topic:
@colucix I love your signature!

paliga · 11-16-2010, 09:01 AM

Quote:

Originally Posted by colucix

No need to invoke external commands in bash:

Code:

2> /tmp/.myname_${PWD//\//-}_$RANDOM

but that wouldnt be one line anymore, since I need a PWD=`pwd`, dont I?

catkin · 11-16-2010, 09:06 AM

Quote:

Originally Posted by paliga

but that wouldnt be one line anymore, since I need a PWD=`pwd`, dont I?

No; $PWD is envalued by bash

colucix · 11-16-2010, 09:11 AM

Quote:

Originally Posted by paliga

but that wouldnt be one line anymore, since I need a PWD=`pwd`, dont I?

Nope. PWD is an internal shell variable: it is automatically updated every time you change directory, as well as OLDPWD, which retains the path of the previous working directory (useful when you use "cd -" to return to the previous location). You can use PWD at any time and it will give you the path of your current working dir. Moreover it is common to all the shells, not only bash.

ghantauke · 11-16-2010, 11:00 AM

I'd recommend you to have a look at "sed" or "tr" commands online rather than copying and pasting what the others have suggested. They are really helpful commands which will come in handy.

colucix · 11-16-2010, 11:29 AM

Quote:

Originally Posted by ghantauke

I'd recommend you to have a look at "sed" or "tr" commands online rather than copying and pasting what the others have suggested.

Indeed sed and tr are very useful commands, but can you explain why they should be better than the efficient and quick shell's parameter substitution?

grail · 11-16-2010, 07:00 PM

I am with colucix ... why reinvent the wheel or use additional applications when the solution is built in

ghantauke · 11-17-2010, 09:05 AM

Quote:

Originally Posted by ghantauke

I'd recommend you to have a look at "sed" or "tr" commands online rather than copying and pasting what the others have suggested. They are really helpful commands which will come in handy.

Your solution is indeed more efficient than mine for this problem. But a combination and tr and sed would be more powerful than the inbuilt substitution alone, for other cases. And learning these commands just take minutes. I'm just trying to make paliga know more about linux commands rather than spoon feed him.

catkin · 11-17-2010, 09:15 AM

Quote:

Originally Posted by ghantauke

But a combination and tr and sed would be more powerful than the inbuilt substitution alone, for other cases. And learning these commands just take minutes.

Especially sed is very powerful and if you can learn it in minutes you are a genius

ghantauke · 11-17-2010, 09:22 AM

Quote:

Originally Posted by catkin

Especially sed is very powerful and if you can learn it in minutes you are a genius

I agree with you. It might take a while to learn about sed from scratch. But if you've programmed before and are familiar with the concept of regular expression already then it'd just take minutes.

paliga · 11-18-2010, 07:49 AM

Well... I would like to direct my thanks to all of you : )

cheerios...