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. That would be so
sed '0 a\
but I get this error:
invalid usage of line address 0 .
What's your suggestion?
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
sed -i '1 i\anything' file
sed -i '1i text' filename
For non-GNU sed
You need to hit the return key immediately after the backslash
1i\ and after
sed -i '1i\ first_line_text '
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 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