How to do a "next line" inside a string?

khaos83 · 02-12-2009, 01:23 AM

Code:

string1=aaa
string2=bbb
newstring=$aaa$bbb

The new string is

Code:

aaabbb

How do i add a "next line" or a \r\n in between the 2 string so that the newstring, when echo, will be

Code:

aaa
bbb

khaos83 · 02-12-2009, 01:51 AM

hm..
i think it is not possible.
or is it not...

i92guboj · 02-12-2009, 01:55 AM

From the echo man page:

Code:

NAME
       echo - display a line of text

SYNOPSIS
       echo [OPTION]... [STRING]...

DESCRIPTION
       Echo the STRING(s) to standard output.

       -n     do not output the trailing newline

       -e     enable interpretation of backslash escapes

       -E     disable interpretation of backslash escapes (default)

       --help display this help and exit

       --version
              output version information and exit

       If -e is in effect, the following sequences are recognized:

       \0NNN  the character whose ASCII code is NNN (octal)

       \\     backslash

       \a     alert (BEL)

       \b     backspace

       \c     suppress trailing newline

       \f     form feed

       \n     new line

       \r     carriage return

       \t     horizontal tab

       \v     vertical tab

Hope it helps.

khaos83 · 02-12-2009, 02:08 AM

i never once thought the critical link lies within echo....

theYinYeti · 02-12-2009, 02:08 AM

Code:

newstring=$string1$'\n'$string2

Yves.

theYinYeti · 02-12-2009, 02:22 AM

Quote:

How do i add a "next line" or a \r\n in between the 2 string so that the newstring, when echo, will be

Code:

aaa
bbb

Note that \r\n is the “new line” for DOS/Windows only. On Unix/Linux, the new line is \n only, and on Mac (at least up to OS9, I don't know for OS10+) the new line is \r only.
If you want to force a DOS new line, then in my previous post, replace $'\n' with $'\r\n'.

Another thing, don't forget that bash and echo have a very HTML-like behaviour with blanks when quotes are omited*: any run of blanks, be it spaces or carriage returns or line feeds… or any mix, is replaced with a single character (the first character of the IFS environment variable, which usually is a space).

Example:

Code:

[yves@localhost ~]$ test1='this is
> test #1'
[yves@localhost ~]$ test2='that      is
test      #2'
[yves@localhost ~]$ echo $test1 $test2
this is test #1 that is test #2
[yves@localhost ~]$ echo "$test1" "$test2"
this is
test #1 that      is
test      #2
[yves@localhost ~]$ echo "$test1"$'\n'"$test2"
this is
test #1
that      is
test      #2
[yves@localhost ~]$ echo $test1$'\n'$test2
this is test #1
that is test #2

Yves.

i92guboj · 02-12-2009, 02:29 AM

Quote:

Originally Posted by theYinYeti

Another thing, don't forget that bash and echo have a very HTML-like behaviour with blanks when quotes are omited*: any run of blanks, be it spaces or carriage returns or line feeds… or any mix, is replaced with a single character (the first character of the IFS environment variable, which usually is a space).
Yves.

Yep. That reminds me of another way to achieve the same effect:

Code:

$ IFS="\n"; echo "1
> 2
> 3
> "
1
2
3

khaos83 · 02-12-2009, 02:37 AM

That's very interesting.
Thanks!