Bash: Add String to the End of the File Without Line Break

Bash: add string to the end of the file without line break

sed '$s/$/yourText2/' list.txt > _list.txt_ && mv -- _list.txt_ list.txt

If your sed implementation supports the -i option, you could use:

sed -i.bck '$s/$/yourText2/' list.txt

With the second solution you'll have a backup too (with first you'll need to do it manually).

Alternatively:

ex -sc 's/$/yourText2/|w|q' list.txt 

or

perl -i.bck -pe's/$/yourText2/ if eof' list.txt

How to append string at the end of text file without leading line break?

You can use sed:

sed -i~ '$ s/$/ bar/' test.txt

• $ is an address that means "the last line". It applies to the following command.
• s/$/ bar/ replaces $, i.e. the end of line, by bar.
• -i (if supported) will change the file in place, leaving the original as a backup (renamed to test.txt~). If your sed doesn't support it, redirect the output to a new file and move it over the old one.

add a string to a file without line break

The -n option controls whether a newline is added at the end of the echo. That very first echo "hello" writes hello\n to the file; that's where the newline is coming from.

To add a kernel option try one of these. Each of them searches for the kernel line in grub.conf and appends " elevator=noop" to the end.

sed '/kernel/ s/$/ elevator=noop/' /etc/grub.conf

awk '$1 == "kernel" { $0 = $0 " elevator=noop" } { print } ' /etc/grub.conf

Append to protected file without creating a new line

You can't. The newline is already there, you can't remove things by appending.

Instead, you would have to replace the content of the file with the changed line.

The easiest way to do so would likely be sed:

sudo sed -i -e 's/$/ fastboot noswap ro/' /boot/cmdline.txt

or paste:

paste /boot/cmdline.txt <(echo fastboot noswap ro) | sudo tee /boot/cmdline.txt

Bash shell script: appending text to a specific line of an existing file without line break

awk '/Options=/ && ! /nodev/ {print $0 ",nodev"; next};1' file

no need to get the line number, just append the ",nodev" to the corresponding line

Is there a way to add text to the end of a string in a conf file in linux?

You can use sed for this purpose.

sed 's/random/& Hello World/' file

to append text to the matched string.

You can use ^random$ to make sure the entire line is matched, before appending.

If you need to modify the file directly, you can use the -i flag, which facilitates in-place editing. Further, using -i.bak creates a backup of the original file first before modifying it, as in

sed -i.bak 's/random/& Hello World/' file

The original copy of the file can be found in file.bak

More about sed : https://www.gnu.org/software/sed/manual/sed.html

How to add newline character at the end of many files

Short and quick tee

But adding a newline at end of each files. For strictly adding a newline at end of files where there are not, please go to second part of this answer!

tee is the tool you're searching for:

Simply:

tee -a <<<'' file1 file2 ...

or

find /path -type f ! -empty -name '*.php' -exec tee -a <<<'' {} +

Warning: Don't miss -a option!

It's very quick, but add a newline on each files.

(You could whipe in a second command like sed '${/^$/d}' -i file1 file2 ... all empty last lines in all files. ;)

(Warning again: I insist: if you miss -a flag for tee command, this will shortly and quickly replace the content of each file found by a newline!! So all your files will become empty!)

Some explanation:

from man tee:

NAME
       tee - read from standard input and write to standard output and files

SYNOPSIS
       tee [OPTION]... [FILE]...

DESCRIPTION
       Copy standard input to each FILE, and also to standard output.

       -a, --append
              append to the given FILEs, do not overwrite

• So tee will reproduce, appending (because of option a), to each file submited as argument, what become on standard input.
• bash feature: "here strings" (see man -Pless\ +/Here.Strings bash), you could use command <<<"here string"" in replacement of echo "here string"| command. For this, bash add a newline to submited string (even empty string: <<<'').

Slower, but stronger

fix newline character after the last line (if not present)

Stay very quick because of limited forks, but one fork to tail -c1 have to be done for each files anyway!

while IFS= read -d '' -r file
do
    IFS= read -d "" chr < <(
        exec tail -c1 "$file"
    )
    if [[ $chr != $'\n' ]]
    then
        echo >> "$file"
    fi   
done < <(
    find . -type f ! -empty -name '*.php' -print0
)

Could by written more compact:

while IFS= read -d '' -r file; do
    IFS= read -d "" chr < <( exec tail -c1 "$file" )
    [[ $chr != $'\n' ]] && echo >> "$file"
done < <( find . -type f ! -empty -name '*.php' -print0 )

• find -print0 print each filename separated by a null character \0.
• IFS= read -d '' -r file don't consider special characters nor spaces, so $file could hold any kind of filename, event containing spaces or accented characters.
• exec tell bash to execute tail as subprocess, avoid default second fork running tail in a subsubprocess.
• tail -c1 read last caracter of $file
• IFS= read -d "" chr store last caracter into $chr variable.

In Bash, how do I add a string after each line in a file?

If your sed allows in place editing via the -i parameter:

sed -e 's/$/string after each line/' -i filename

If not, you have to make a temporary file:

typeset TMP_FILE=$( mktemp )

touch "${TMP_FILE}"
cp -p filename "${TMP_FILE}"
sed -e 's/$/string after each line/' "${TMP_FILE}" > filename

---

Related Topics