I've been looking around sed command to add text into a file in a specific line. This works adding text after line 1:

sed '1 a\

But I want to add it before line 1. It would be:

sed '0 a\

but I get this error: invalid usage of line address 0.

Any suggestion?


16 Answers 16


Use sed's insert (i) option which will insert the text in the preceding line.

sed '1 i\

Question author's update:

To make it edit the file in place - with GNU sed - I had to add the -i option:

sed -i '1 i\anything' file

Also syntax

sed  -i '1i text' filename

For non-GNU sed

You need to hit the return key immediately after the backslash 1i\ and after first_line_text:

sed -i '1i\

Also note that some non-GNU sed implementations (for example the one on macOS) require an argument for the -i flag (use -i '' to get the same effect as with GNU sed).

For sed implementations that does not support -i at all, run without this option but redirect the output to a new file. Then replace the old file with the newly created file.

  • 1
    It doesn't work without -i option. I'll update your answer before accepting.
    – Manolo
    Commented Nov 8, 2013 at 12:07
  • 1
    thanks. What OS are you using? Original solution worked on OpenSuse 9.
    – suspectus
    Commented Nov 8, 2013 at 12:22
  • 1
    Interesting! I'm on Lubuntu 13.10 and sed '1 i\this text is entered above the existing first line' file works for me.
    – user15760
    Commented Nov 8, 2013 at 13:47
  • 2
    Here, using sed (GNU sed) 4.2.2 just sed '1 i text to insert' -i file worked like a charm. Thanks
    – ton
    Commented Feb 15, 2016 at 14:06
  • 6
    Does not work on empty files.
    – rudimeier
    Commented Sep 28, 2016 at 20:32

Echo is used to get the text. Cat filename - prints the file in the console and > uses it to send to another file filename1 and then we move filename1 to filename to get the text inserted to the first line of desired file.

  (echo "some text" && cat filename) > filename1 && mv filename1 filename
  • 12
    Please let me know why the following is downvoted
    – Ankit Shah
    Commented Jan 9, 2017 at 14:58
  • 2
    Perhaps because the OP mentions sed. That does not deserve a down vote in my opinion. That solution was even the best fitting my needs, then upvoted.
    – рüффп
    Commented Apr 12, 2018 at 10:46
  • 1
    I upvoted. works on ksh for me.
    – arcee123
    Commented Aug 22, 2019 at 13:47
  • 3
    this is great solutions! it work in Makefile & MacOS well.
    – zx1986
    Commented Jun 18, 2020 at 23:33
  • 1
    1. Sed is installed everywhere 2. This is not an elegant solution : You call 1 builtin + cat + mv instead of just calling one command. Imagine the waste of time if this solution is used as part of a script that will run it thousands of time.
    – binarym
    Commented Jun 10, 2022 at 9:09

You can use the POSIX tool ex:

ex a.txt <<eof
1 insert



Using GNU awk >= 4.1:

awk -i inplace 'BEGINFILE{print "first line"}{print}' foo.sh

In opposite to all the sed answers, this works on empty files too.

  • 1
    inplace is a library, and unfortunately it appears on all awk distributions ship it. I get "awk: fatal: can't open source file 'inplace' for reading" GNU Awk 4.2.1, API: 2.0 (GNU MPFR 4.0.1, GNU MP 6.1.2)
    – vossad01
    Commented Jul 8, 2018 at 14:15
sed  -i '1i new_text' file_name

If you don't specify the -i option, it won't show any error, and displays the output on standard terminal, but doesn't insert the text in the file.

  • The question is not about the -i switch. Commented Mar 14, 2016 at 20:30
  • How do you figure that?  It is an answer to the question.  Yes, it's similar to the accepted answer, but not exactly the same. Commented Mar 14, 2016 at 22:51
  • @G-Man - one might argue the template used by cas is far from ideal but really, this is similar like in nearly identical... the difference being the spacing and the fact this one has no backslash. As far as I am concerned they are technically identical (as they are both gnu sed specific and it just happens that gnu sed will accept the i without a backslash). If others think this warrants a separate answer + an upvote... oh well. Commented Mar 15, 2016 at 0:41

You want to insert text before the first line rather than append it after, so use

sed '1 i\
your_text' your_file

A here document can also help:

cat /dev/stdin your_file <<EOI
Your text
goes here

The 0a command you attempted does work in ex, the predecessor to vi:

printf '%s\n' 0a 'Anything you want to add' . x | ex file.txt

The printf command by itself outputs:

Anything you want to add

The 0a means append after the 0th line (i.e. before the first line).

The next line or multiple lines is literal text to be added.

The . on a line by itself terminates the "append" command.

The x causes Ex to save the changes to the file and exit.


I am surprised that in this old question nobody has shown the most common (and quite simple in this case) sed command:

$ sed  -i '1s/^/new_text\
/' file_name

Which works in most shells and is portable to several sed versions, provided that the file contains at least one valid line.
If GNU sed is available, you may use this:

$ sed -i '1s/^/new_text\n' file_name

The difference is that GNU sed allow the use of a \n for a newline and others need a literal newline preceded by a backslash (which also work in GNU sed anyway).

If a shell which accepts the $'…' syntax is in use, you may insert the newline directly, so sed sees that the newline is already there:

$ sed -i $'1s/^/new_text\\\n/' file_name

Which works for more sed versions.

If the file has no lines (i.e: its empty) just:

$ echo "new_text" > file_name
  • What if there is no lines in the file? Commented Jan 9, 2020 at 7:21
  • @Justalearner The title of the question asks for: insert text before the first line of a file, so, a first line must already exist. That is also a problem for the selected answer.
    – user232326
    Commented Jan 13, 2020 at 19:04
  • Amazing answer @Isaac. This is certainly the only solution which works in the literal sense. I needed to add "schema": before the first line without any new line to be added. Your solution work -> sed -i '1s/^/"schema":/' o
    – nitinr708
    Commented Apr 1, 2020 at 19:13

I had issues with BSD sed (MacOS) and inserting text from a variable, so this is how I did it:

sed -i '' -e "1{x;s/^.*/$headers/p;x;} some_file"


  • 1{...} This affects only the first line
  • x swap the current line with the hold space (currently empty)
  • s/../../p replaces (the now empty line) with the expected text (this avoids the line-break problem) and outputs it (so the first line will be get printed)
  • x swap again, retrieving the file first line which was in the hold space into the pattern space

To insert text to the first line and put the rest on a new line using sed on macOS this worked for me

sed -i '' '1 i \
' ~/Downloads/File-path.txt

Unfortunately, all the answers above (mostly with sed) didn't work out for me since they all substituted the first line. I am on an Ubuntu 16.04 LTS machine. Here is my workaround with GNU Awk 4.0.2:

awk '{if(NR==1){$0="NEW_FIRST_LINE"$0; print $0} ;if(NR!=1){print $0}}' file_name
  • 2
    Not sure what you're talking about... There's only one sed answer that uses replacement but it doesn't substitute the existing line. Commented Nov 15, 2018 at 18:06

Adding the text hello before the first line without a carriage return or line feed to the file myfile

sed -i '1s/^/hello /' myfile

This will also not output the entire file on the terminal.

  • perfect for appending spend 1 hour then got your solution
    – user765443
    Commented Jun 19, 2023 at 11:59
echo -e "task goes here\n$(cat todo.txt)" > todo.txt

echo "task goes here
$(cat todo.txt)" > todo.txt

echo 'task goes here'$'\n'"$(cat todo.txt)" > todo.txt



If anyone is interested, my problem was to insert same header line into several files. Thanks to proposed solution, I came up with this :

sed -i 1i\ $(cat header_line) data.csv

where header_line is a file containing desired first line ,


Just similar to Ankit Shah's answer:

(echo "some text" && cat filename) > /tmp/filename && cat /tmp/filename > filename

It's not convenient to use such a long command, so I create a simple bash function (in .bashrc or elsewhere possible) as following:

echo0 () {
  (echo ${@:2} && cat $1) > /tmp/$1
  cat /tmp/$1 > $1
# $1 is your-file-name, ${@:2} are contents after "your-file-name".
# How to use:
#   > echo0 myfile hellow world etc.
#   > head myfile
#     hellow world etc.
#     ...

sed can insert (multiple times) before the first and after the last

I would assume that anyone who searched for how to insert/append text to the beginning/end of a file probably also needs to know how to do the other also.

cal |                            \
  gsed -E                        \
       -e     '1i\{'             \
       -e     '1i\  "lines": ['  \
       -e 's/(.*)/    "\1",/'    \
       -e '$s/,$//'              \
       -e     '$a\  ]'           \
       -e     '$a\}'


This is cal output piped to gnu-sed (called gsed on macOS installed via brew.sh) with extended RegEx (-E) and 6 "scripts" applied (-e) and line breaks escaped with \ for readability.

  • Scripts 1 & 2 use 1i\ to "at line 1, insert".
  • Scripts 5 & 6 use $a\ to "at line <last>, append".
    • I vertically aligned the text outputs to make the code represent what is expected in the result.
  • Scripts 3 & 4 do substitutions
    • Script 4 applies only to "line <last>" because of the $ placed before the s/.

The result is converting command output to valid JSON.


  "lines": [
    "    October 2019      ",
    "Su Mo Tu We Th Fr Sa  ",
    "       1  2  3  4  5  ",
    " 6  7  8  9 10 11 12  ",
    "13 14 15 16 17 18 19  ",
    "20 21 22 23 24 25 26  ",
    "27 28 29 30 31        ",
    "                      "
  • While I haven't voted on your question, note that we already have several answers, including an accepted one, that demonstrate the desired result.
    – Jeff Schaller
    Commented Oct 22, 2019 at 12:12
  • @JeffSchaller The Stack Exchange community is not a forum. Its purpose extends beyond helping the OP get unblocked. The goal is to seed the global knowledge base with many options that seekers can stumble upon when searching for answers. The reason I titled my answer is to help users recognize the utility of this answer before they even click the Google result. Commented Oct 22, 2019 at 16:09
  • 3
    What I'm saying is that your answer isn't providing any new options (answers) for future readers of this question. We already have four answers that use variations of 1i to insert text before the first line. Someone with this question would have to extract the parts they need from your answer in order to solve their problem. Questions are free, so I'd invite you to ask & answer your own question in order to provide your specific answer.
    – Jeff Schaller
    Commented Oct 22, 2019 at 16:19

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