[SOLVED] problem with ' set $(cat crpage)'

boumphreyfr · 04-27-2011, 01:04 PM

I have several lines of text that I want to sort by line and display

Code:

#!/bin/bash 
crpage="
                               NEW YORK
                         HENRY HOLT AND COMPANY
                                  1916
                       [several more lines...] 
                     J. R., L. E. W., and L. T. S.,
                  without whose help this small record
                      could not have been written."

	IFS=$'\n'
	set $(cat crpage) 
        echo $1
        echo $2
        echo $15
exit

The proble is $1 and $2 show the first and second ine but $15 shows:
NEW YORK5
In other words line 1 !!

Ie tried quotes with no success. Any ideas?

David the H. · 04-27-2011, 01:26 PM

Positional parameters larger than 9 need to use the full variable form: "${15}".

And from now on, please use [code][/code] tags around your code, to preserve formatting and to improve readability.

boumphreyfr · 04-27-2011, 03:01 PM

Thankyou
My first post didn't know about [code][code] ,should have RTFM
Frank
P.S.
I have now added code tags

David the H. · 04-28-2011, 07:37 AM

Not to worry. It's common with newcomers.

Although I would've put the ending tag after the last line of code instead of the end of the post.

A couple more things to comment on:

You can usually use redirections instead of cat when accessing file contents. In this case you can use:

Code:

set $( <crpage )

Personally, I don't like using set/shift with the positional parameters. I prefer to use arrays instead. Bash v.4 even has a new mapfile built-in that makes it easy to load lines from a file into an array.

Code:

mapfile -t arr <crpage     #-t removes the trailing newline
     
#or for earlier versions of bash:
#IFS=$'\n'
#arr=( $(<crpage) )

echo "${arr[0]}"           #you should generally quote variable expansions
echo "${arr[1]}"           #especially when they can contain spaces
echo "${arr[14]}"          #and other shell-reserved characters

There's no need to fool with IFS this way either (at least, not with v.4). The only thing you have to remember is that arrays are 0-indexed, so you need to subtract one from each line number to reference it.

(Or mapfile also has an -O option, which lets you set the index start number to whatever you want.)