[SOLVED] Alias or Function of LS

inferno1980 · 10-24-2014, 05:30 AM

Hi
How can I create alias (or function) of following command;

Code:

ls -lh --color | awk '{printf("%5s %s\n",$5,$9)}'

because putting following:

Code:

alias ls='ls -hl --color | awk '{printf("%5s %s\n",$5,$9)}''

in .bashrc is not working.
Thanks

Ztcoracat · 10-24-2014, 08:36 AM

Hi:

These articles have other alternative's to using alias with a cmd-

Code:

example:
alias newcommand='yourcommand -arguments'

http://linuxreviews.org/quicktips/alias/

You can use alias with a script if that helps.
http://www.cyberciti.biz/tips/bash-a...inux-unix.html

Using bash with alias and awk-
http://stackoverflow.com/questions/7...as-or-function
http://superuser.com/questions/69641...an-awk-command

Hope that helps.

inferno1980 · 10-24-2014, 09:54 AM

It means that I have to create a function. I have created following function:

Code:

ls (){ ls -lh --color | awk '{printf("%5s %s\n",$5,$9)}' ;}

but its not working and uplon executing command 'ls', the system becomes unresponsive for a while.
PS. Although 'ls' is already a command, but I still want to create a function with name 'ls'. I hope it wouldn't do any harm.

grail · 10-24-2014, 10:50 AM

Well I assume you are aware that once you alias 'ls' this way you won't get your normal output when issuing the 'ls' command.

Secondly I am hoping the command works better for you than me as the output was particularly useless and not what I would be expecting seeing the awk command implies
it would return 2 items ... here is a sample of what I get when I run your command:

Code:

$ ls -lh --color | awk '{printf("%5s %s\n",$5,$9)}'
      
  16K 
 4.0K 
 4.0K 
 4.0K 
    0 
 2.0K

As for creating an alias or function I would see no real reason why it wouldn't work. Try doing it in multiple steps to confirm where you are getting an issue?

A side note, I presume you have already checked that 'ls' is not already aliased to something else which may conflict with what you are doing??

inferno1980 · 10-24-2014, 04:01 PM

'ls' working here fine, here is the output;

Code:

1:58:25 ~>ls -lh --color | awk '{printf("%5s %s\n",$5,$9)}'
 4.0K audio
 4.0K Desktop
 4.0K downloads
 4.0K picture
 4.0K software
 4.0K text
 4.0K video

ls is not conflicting with any other alias as i have disabled the alias 'ls --color'.
How can I set it in multiple steps?

grail · 10-24-2014, 10:39 PM

Well you mention that it hangs so assign just the ls part to an alias and confirm it works, then do the same for the awk part (might have to pipe an echo to it).

I would also mention that whilst your -l is returning the expected number of columns (as mine has only eight) that if any of your file or directory names contain whitespace, your awk will come unstuck
and you will only get the first word

rknichols · 10-24-2014, 11:05 PM

Quote:

Originally Posted by inferno1980

It means that I have to create a function. I have created following function:

Code:

ls (){ ls -lh --color | awk '{printf("%5s %s\n",$5,$9)}' ;}

but its not working and uplon executing command 'ls', the system becomes unresponsive for a while.
PS.

Of course. The function is just recursively invoking itself. You need to use the command builtin or use the full pathname to bypass the function lookup.

Code:

ls (){ command ls -lh --color | awk '{printf("%5s %s\n",$5,$9)}' ;}
ls (){ /bin/ls -lh --color | awk '{printf("%5s %s\n",$5,$9)}' ;}

The other problem you will have is that there is no way to pass any arguments to this function. That's fine, as long as you never want a listing for anything but the current directory.

Code:

ls (){ command ls -lh --color "$@" | awk '{printf("%5s %s\n",$5,$9)}' ;}

But, IMHO it's pretty silly to replace a basic system command like ls with some special-purpose function.

inferno1980 · 10-25-2014, 06:49 AM

This function did the trick:

Code:

ls (){ /bin/ls -lh --color | awk '{printf("%5s %s\n",$5,$9)}' ;}

Thanks a lot

inferno1980 · 10-25-2014, 10:22 AM

There is a flaw

'ls' is not showing the part of the file name name which is after space i.e. if a file is named 'mobile videos', ls is only showing 'mobile'. How can I fix it?

rknichols · 10-25-2014, 11:35 AM

awk doesn't have a simple way to reference "the rest of the line starting with field 9." Simplest is to use a regex to separate the first 8 fields from the rest.

Code:

ls (){ LC_TIME=C /bin/ls -lh --color | awk --re-interval '{match($0,"([^ ]+ +){8}(.*)",aa); printf("%5s %s\n",$5,aa[2])}' ;}

Analysis of that regex is left as an exercise.

Note that I have also passed "LC_TIME=C" to ls since your locale settings can affect whether the date is printed as one field or two (i.e., "Oct 25" vs. "2014-10-25").

inferno1980 · 10-25-2014, 01:57 PM

Quote:

Originally Posted by rknichols

awk doesn't have a simple way to reference "the rest of the line starting with field 9." Simplest is to use a regex to separate the first 8 fields from the rest.

Code:

ls (){ LC_TIME=C /bin/ls -lh --color | awk --re-interval '{match($0,"([^ ]+ +){8}(.*)",aa); printf("%5s %s\n",$5,aa[2])}' ;}

Analysis of that regex is left as an exercise.

Note that I have also passed "LC_TIME=C" to ls since your locale settings can affect whether the date is printed as one field or two (i.e., "Oct 25" vs. "2014-10-25").

Thanks a lot man

Now its working perfectly. If you live near to me, I will definitely invite you to have a coffee with me