Append to end to line without newline

bashcommand lineechosed

When i try to append to the end of a file it creates a new line. Now I have tried to fix this with echo -n but that doenst work.

So what am I trying. I'm trying to get the following result:

Hello
This
Is
A
Test

But when I Append text with echo with

echo -n "Test2" >> file.txt

The following thing happens:

Hello
This
Is
A
Test
Test2

But what I want is:

Hello
This
Is
A
Test Test2

How am I able to do this? I have tried sed,echo and printf but none of these give the right result

Best Answer

With sed:

sed '$s/$/ Test2/' file

truncate -s-1 file
echo -n " Test2" >> file

Output:

Hello
This
Is
A
Test Test2

Related Solutions

Macos – Use OS X’s sed in a script to find a string and append a line beneath it including a newline character

Nevermind. While reformatting the code portion of this question, a solution became clear:

I found that the following does exactly what I need:

sed '/match string/  a\
newline string \
' ./inputfile > ./outputfile

Colorized bash prompt overwrites previous command’s output if the output doesn’t end with a newline

My preferred solution is simply to have the prompt always begin with a newline. That way I always have a blank line between the last command output (except in this case, of course), which feels more natural to me. And the worst case is that instead of overwriting text like you are seeing, I don't get the blank line in between. Unless you try it out for a while and simply can't stand the blank line, I highly recommend it.

PS1='\n\[\033[1;32m\]\u@\h\[\033[0m\]:\[\033[1;34m\]\w\[\033[0m\]\$ '

An additional suggestion, if you're up for it: I also use a multi-line prompt to make my command line as long as possible before wrapping (or scrolling if your terminal or shell is configured for that). I also like to know the history line number. Those two together:

PS1='\n\[\033[1;32m\]\u@\h\[\033[0m\]:\[\033[1;34m\]\w\[\033[0m \!\]\n\$ '

Finally, I also like to get timestamps printed before and after running commands. A simplified version of what I use for that is:

export PROMPT_COMMAND="date +\"%Y-%m-%d %H:%M:%S (%s)\"; trap 'date +\"%Y-%m-%d %H:%M:%S (%s)\"; trap DEBUG' DEBUG"

Head spinning yet? :)

Best Answer

Related Solutions

Macos – Use OS X’s sed in a script to find a string and append a line beneath it including a newline character

Colorized bash prompt overwrites previous command’s output if the output doesn’t end with a newline

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