Differences between revisions 4 and 6 (spanning 2 versions)
Revision 4 as of 2008-11-22 23:33:03
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Editor: GreyCat
Comment: first-line and clean up of English
Revision 6 as of 2009-01-11 09:31:26
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Editor: ppp089210047077
Comment: ed sucks
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ex will also add a newline character to the end of the file if it's missing.

How do I prepend a text to a file (the opposite of >>)?

You cannot do it with bash redirections alone; the opposite of >> does not exist....

To insert content at the beginning of a file, you can use an editor:

ex file << EOF
0a
header line 1
header line 2
.
w
EOF

ex will also add a newline character to the end of the file if it's missing.

Or you can rewrite the file, using things like:

{ echo line; cat file ;} >tmpfile && mv tmpfile file
echo line | cat - file > tmpfile && mv tmpfile file

or lots of other solutions.

BashFAQ/090 (last edited 2017-02-14 19:48:12 by GreyCat)