[SOLVED] how to escape breakline?

webhope · 05-13-2010, 04:41 AM

How to escape breaklines to \n?
${content[$n]} contains chars like (), spaces and /.

To me, this doesn't work:

Code:

content_block=$(echo ${content[$n]} | awk 'BEGIN { FS="\n"; RS="";}  {b = gensub(/(\n)/, "\\\\n", "g"); print b }')

It looks like awk is not good solution for this.

catkin · 05-13-2010, 05:19 AM

May we know the value of ${content[$n]} and what an "escape breakline" is? When you ask "How to remove escape breaklines to \n?" do you mean "How to change escape breaklines to \n?"

webhope · 05-13-2010, 05:24 AM

Quote:

Originally Posted by catkin

May we know the value of ${content[$n]} and what an "escape breakline" is? When you ask "How to remove escape breaklines to \n?" do you mean "How to change escape breaklines to \n?"

Sorry I wanted to write to escape breaklines.

text

Code:

title Sata Mandriva kernel
(hd0,2)/boot/vmlinuz BOOT_IMAGE=linux root=(hd0,2)  resume=UUID=e12487ff-6d6f-44c4-9e03-33f545b3b798 splash=silent vga=788
initrd (hd0,2)/boot/initrd.img

catkin · 05-13-2010, 05:36 AM

Quote:

Originally Posted by webhope

Sorry I wanted to write to escape breaklines.

text

Code:

title Sata Mandriva kernel
(hd0,2)/boot/vmlinuz BOOT_IMAGE=linux root=(hd0,2)  resume=UUID=e12487ff-6d6f-44c4-9e03-33f545b3b798 splash=silent vga=788
initrd (hd0,2)/boot/initrd.img

OK but what does "escape breaklines" mean? What is a breakline?

I took your data and command, hoping what you want would become clear but it didn't help. How does the output below differ from what you want?

Code:

c@CW8:~$ content[1]='title Sata Mandriva kernel
> (hd0,2)/boot/vmlinuz BOOT_IMAGE=linux root=(hd0,2)  resume=UUID=e12487ff-6d6f-44c4-9e03-33f545b3b798 splash=silent vga=788
> initrd (hd0,2)/boot/initrd.img'
c@CW8:~$ echo ${content[1]} | awk 'BEGIN { FS="\n"; RS="";}  {b = gensub(/(\n)/, "\\\\n", "g"); print b }'
title Sata Mandriva kernel (hd0,2)/boot/vmlinuz BOOT_IMAGE=linux root=(hd0,2) resume=UUID=e12487ff-6d6f-44c4-9e03-33f545b3b798 splash=silent vga=788 initrd (hd0,2)/boot/initrd.img

webhope · 05-13-2010, 05:57 AM

Well breakline is the invisible \n . (edit - proper: new line!)
End escape the invisible breakline (or break line?) means to transform invisible \n to visible: \n:

Target string should look like this:
'title Sata Mandriva\nkernel (hd0,2) ...\n...'

My command cannot work. Cannot change the character because there is not breakline \n . It was removed because of the file separator.

grail · 05-13-2010, 06:24 AM

How about:

Code:

echo ${content[$n]} | awk '{printf "%s\\n",$0}'

webhope · 05-13-2010, 06:34 AM

Quote:

Originally Posted by grail

How about:

Code:

echo ${content[$n]} | awk '{printf "%s\\n",$0}'

I think this doesn't do what I wanted

Code:

# content[1]='title Sata Mandriva kernel
> (hd0,2)/boot/vmlinuz BOOT_IMAGE=linux root=(hd0,2)  resume=UUID=e12487ff-6d6f-44c4-9e03-33f545b3b798 splash=silent vga=788
> initrd (hd0,2)/boot/initrd.img'
#
# echo ${content[1]} | awk '{printf "%s\\n",$0}'
title Sata Mandriva kernel (hd0,2)/boot/vmlinuz BOOT_IMAGE=linux root=(hd0,2) resume=UUID=e12487ff-6d6f-44c4-9e03-33f545b3b798 splash=silent vga=788 initrd (hd0,2)/boot/initrd.img\n

Problem is that the \n is only on the end of string; but I need it on every end of line.

grail · 05-13-2010, 06:47 AM

Where are your quotes to preserve the white space??

Code:

#!/bin/bash

content[1]='title Sata Mandriva kernel
(hd0,2)/boot/vmlinuz BOOT_IMAGE=linux root=(hd0,2)  resume=UUID=e12487ff-6d6f-44c4-9e03-33f545b3b798 splash=silent vga=788
initrd (hd0,2)/boot/initrd.img'

echo "${content[1]}" | awk '{printf "%s\\n",$0}'

Output:

Code:

title Sata Mandriva kernel\n(hd0,2)/boot/vmlinuz BOOT_IMAGE=linux root=(hd0,2)  resume=UUID=e12487ff-6d6f-44c4-9e03-33f545b3b798 splash=silent vga=788\ninitrd (hd0,2)/boot/initrd.img\n

webhope · 05-13-2010, 07:01 AM

Grail, you have truth. The quotes are the magic! Thanx!

webhope · 05-13-2010, 07:34 AM

Is it possible to implement your solution to this code?

I have this command to escape some characters:

Code:

original_block=$(echo ${original_content[$n]} | awk 'BEGIN { FS="\n"; RS="";}  {b = gensub(/([\]*+/])/, "\\\\&", "g"); print b }')

Now to add the replace command of breaklines (to \n)

grail · 05-13-2010, 07:52 AM

Yes if you get rid of the BEGIN{}

webhope · 05-13-2010, 09:11 AM

How to do it?

I would try #3 but I need to escape the characters. In #3 they are not escaped.

Code:

#1 - 1st I need to escape some characters but it removes the \n
original_block=$(echo ${original_content[$n]} | awk 'BEGIN { FS="\n"; RS="";}  {b = gensub(/([\]*+/])/, "\\\\&", "g"); print b }')

#2 - not working
original_block=$(echo "$original_block" | awk '{printf "%s\\n",$0}');

#3 - working
original_block=$(echo "${original_content[$n]}" | awk '{printf "%s\\n",$0}');

grail · 05-13-2010, 09:16 AM

Code:

#!/bin/bash

content[1]='title Sata Mandriva kernel
(hd0,2)/boot/vmlinuz BOOT_IMAGE=linux root=(hd0,2)  resume=UUID=e12487ff-6d6f-44c4-9e03-33f545b3b798 splash=silent vga=788
initrd (hd0,2)/boot/initrd.img'

echo "${content[1]}" | awk '{b = gensub(/([\]*+/])/, "\\\\&", "g"); printf "%s\\n",b }'

webhope · 05-13-2010, 09:27 AM

Quote:

Originally Posted by webhope

How to do it?

I would try #2 but I need to escape the characters. In #2 they are not escaped.

I think I said it wrong. #2 was not working because of escaped characters and removed \n . #3 was working but having not escaped characters

webhope · 05-13-2010, 09:32 AM

Quote:

Originally Posted by grail

Code:

echo "${content[1]}" | awk '{b = gensub(/([\]*+/])/, "\\\\&", "g"); printf "%s\\n",b }'

Thank you this is workable.