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Apparently, though unproven, at 13:25 on Saturday 12 February 2011, |
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meino.cramer@×××.de did opine thusly: |
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> Hi, |
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> |
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> I am trying to instruct sed to insert a line of text before |
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> a matched line. The whole command should fit into one |
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> physical (command) line. |
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> |
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> Is it possible? And how is it possible? |
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> |
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> Thank you very much for any hint in advance! |
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> Best regards, |
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> mcc |
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There's nothing special about a line, it's just a bunch of characters that end |
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with a newline (itself just a character). |
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But you can't insert stuff at arbitrary points, you can only replace stuff |
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with other stuff. You can replace the start of line marker (^), so do this: |
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$ cat sed.txt |
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1 |
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2 |
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$ cat sed.txt | sed -e 's/^/a\n/g' |
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a |
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1 |
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a |
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2 |
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I replaced "start of line" with "a and a newline". Modify the regex to suit |
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your needs. This gets awkward though, as you can search with a regex but only |
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replace a literal. If you need to insert some line before any line containing |
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say a "z" for example, then that is way beyond sed's capabilities and you are |
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into awk|perl territory. |
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You didn't clearly state what you are trying to do with examples, so the above |
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vague wishy-washy goop is the best I can do for you. |
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-- |
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alan dot mckinnon at gmail dot com |
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