How to Insert a New Line in Linux Shell Script

How to insert a new line in Linux shell script?

The simplest way to insert a new line between echo statements is to insert an echo without arguments, for example:

echo Create the snapshots
echo
echo Snapshot created

That is, echo without any arguments will print a blank line.

Another alternative to use a single echo statement with the -e flag and embedded newline characters \n:

echo -e "Create the snapshots\n\nSnapshot created"

However, this is not portable, as the -e flag doesn't work consistently in all systems. A better way if you really want to do this is using printf:

printf "Create the snapshots\n\nSnapshot created\n"

This works more reliably in many systems, though it's not POSIX compliant. Notice that you must manually add a \n at the end, as printf doesn't append a newline automatically as echo does.

How can I have a newline in a string in sh?

If you're using Bash, you can use backslash-escapes inside of a specially-quoted $'string'. For example, adding \n:

STR=$'Hello\nWorld'
echo "$STR" # quotes are required here!

Prints:

Hello
World

If you're using pretty much any other shell, just insert the newline as-is in the string:

STR='Hello
World'

Bash recognizes a number of other backslash escape sequences in the $'' string. Here is an excerpt from the Bash manual page:

Words of the form $'string' are treated specially. The word expands to
string, with backslash-escaped characters replaced as specified by the
ANSI C standard. Backslash escape sequences, if present, are decoded
as follows:
      \a     alert (bell)
      \b     backspace
      \e
      \E     an escape character
      \f     form feed
      \n     new line
      \r     carriage return
      \t     horizontal tab
      \v     vertical tab
      \\     backslash
      \'     single quote
      \"     double quote
      \nnn   the eight-bit character whose value is the octal value
             nnn (one to three digits)
      \xHH   the eight-bit character whose value is the hexadecimal
             value HH (one or two hex digits)
      \cx    a control-x character

The expanded result is single-quoted, as if the dollar sign had not
been present.

A double-quoted string preceded by a dollar sign ($"string") will cause
the string to be translated according to the current locale. If the
current locale is C or POSIX, the dollar sign is ignored. If the
string is translated and replaced, the replacement is double-quoted.

How to insert a newline in front of a pattern?

Some of the other answers didn't work for my version of sed.
Switching the position of & and \n did work.

sed 's/regexp/\n&/g' 

Edit: This doesn't seem to work on OS X, unless you install gnu-sed.

Insert newline (\n) using sed

The sed on BSD does not support the \n representation of a new line (turning it into a literal n):

$ echo "123." | sed -E 's/([[:digit:]]*)\./\1\n next line/'
123n next line

GNU sed does support the \n representation:

$ echo "123." | gsed -E 's/([[:digit:]]*)\./\1\nnext line/'
123
next line

Alternatives are:

Use a single character delimiter that you then use tr translate into a new line:

$ echo "123." | sed -E 's/([[:digit:]]*)\./\1|next line/' | tr '|' '\n'
123
next line

Or use an escaped literal new line in your sed script:

$ echo "123." | sed -E 's/([[:digit:]]*)\./\1\
next line/'
123
next line

Or define a new line:

POSIX:

nl='
'

BASH / zsh / others that support ANSI C quoting:

nl=$'\n'

And then use sed with appropriate quoting and escapes to insert the literal \n:

echo "123." | sed 's/\./'"\\${nl}"'next line/'
123
next line

Or use awk:

$ echo "123." | awk '/^[[:digit:]]+\./{sub(/\./,"\nnext line")} 1'
123
next line

Or use GNU sed which supports \n

how to insert newline in a already existing BASH string on the command line

You can use two shortcuts to do that ctrl + k and ctrl + y:

echo "some command" && echo "some other long command"

Now move cursor somewhere (in my example, cursor is marked by >):

echo "some command" && > echo "some other command"

Now press ctrl + k - this will cut everything after a cursor:

echo "some command" && >

Now put \ (backslash) and press enter:

echo "some command" && \
>

And now paste the part you've previously cut by ctrl + y:

echo "some command" && \
echo "some other long command"

---

Edit: to move more easily around in a long command, you can use shortcuts:

• alt + b - move one word backwards (on Mac OS X: ESC + b)
• alt + f - move one word forwards (on Mac OS X: ESC + f)

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Ultra-solution

You can also open current line in a editor using Ctrl-x + Ctrl-e (two shortcuts, one after another). Then edit it just as a regular text file, save & quit and voila, edited command will execute.

If you want to choose which editor to use, just set EDITOR environment variable.

How can I insert a new line after each character in shell script?

There is a tool called fold which inserts linebreaks, and you can tell it do add one after every character:

$ fold -w 1 <<< 'abcdefghi'
a
b
c
d
e
f
g
h
i

<<< is used to indicate a here string. If your shell doesn't support that, you can pipe to fold instead:

echo 'abcdefghi' | fold -w 1

Echo newline in Bash prints literal \n

Use printf instead:

printf "hello\nworld\n"

printf behaves more consistently across different environments than echo.

How do I add a line break for read command?

I like Huang F. Lei's answer, but if you don't like the literal line break, this works:

read -p "Please Enter a Message: `echo $'\n> '`" message

Shows:

Please Enter a Message:
> _

...where _ is where the cursor ends up. Note that since trailing newlines are usually dropped during command substitution, I've included the > afterward. But actually, your original question doesn't seem to want that prompt bit, so:

# Get a carriage return into `cr` -- there *has* to be a better way to do this
cr=`echo $'\n.'`
cr=${cr%.}

# Use it
read -p "Please Enter a Message: $cr" message

Shows

Please Enter a Message:
_

There has to be a better way, though.

Linux script to insert in a file a new line

try this;

sed -i '/# Load Java configuration/i JBOSS_User=root'  ITg.conf

before this command, make backup as below;

cp ITg.conf ITg.conf_backup

man sed :

-i[SUFFIX], --in-place[=SUFFIX]

              edit files in place (makes backup if SUFFIX supplied)

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