How do I move a line in a file to the top from the command line?

Question

I would like to move a path in a file to the top of the file. Each path is listed 1 per line. How do I move /someplace/2nd/ to the top using only the command line?

/someplace/1st/
/someplace/2nd/
/someplace/3rd/

So I end up with

/someplace/2st/
/someplace/1nd/
/someplace/3rd/

Answer 1

Since you used the vim tag I'll assume first that you meant Vim's command line. If that's the case, then this command will do it.

:g/^\/someplace\/2nd\/$/m0

where that last character is a zero. See

:help :g
:help :m

In the event that you meant the shell command line, you can use vim to edit your file using this command.

vim -c 'g/^\/someplace\/2nd\/$m0' -cwq yourfile

See

:help -c
:help :wq

Answer 2

The traditional way to edit files in place non-interactively is by using ed:

(echo '/^\/someplace\/2nd\/$/m0'; echo w; echo q ) | ed $file

That sends 3 commands to the ed text editor running on the file $file:

• /regular_expression/m0: search for a line matching regular_expression and move it to position 0
• w: write the file
• q: quit

Answer 3

{
  sed -n '/^\/someplace\/2nd\//{p;q}' file
  sed    '/^\/someplace\/2nd\//d' file
} > temp && mv temp file

Answer 4

This might work for you (GNU sed):

sed -i '1,\|/someplace/2nd/|{1{h;d};//!{H;d};G}' file