Timeline for How do I add text to the beginning of a file in Bash?
Current License: CC BY-SA 4.0
23 events
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| S Oct 15, 2020 at 15:27 | history | suggested | Lanre | CC BY-SA 4.0 |
Add similar commands on mac os x
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| Oct 13, 2020 at 8:29 | review | Suggested edits | |||
| S Oct 15, 2020 at 15:27 | |||||
| Jun 19, 2020 at 10:20 | comment | added | stephanmg | Is this also Sh compatible? | |
| Jan 31, 2020 at 15:20 | comment | added | Xælias | For what it's worth the cat version is around 3 times faster than the sed ones. At least on the test in did on a ~4GB file. | |
| Mar 13, 2019 at 15:06 | comment | added | Simon Lindholm |
The sed versions don't seem to work on an empty file.
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| Sep 29, 2017 at 18:17 | review | Suggested edits | |||
| Sep 29, 2017 at 19:18 | |||||
| Jul 20, 2016 at 21:14 | comment | added | Terrance |
@DennisWilliamson Unfortunately the sed doesn't recognize the \t as tab. I forgot to say that I had to do it as echo -e to make it work with the tab.
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| Jul 20, 2016 at 21:07 | comment | added | Dennis Williamson |
@Terrance: If your sed command looks something like this (inserting a leading tab): '1i\tSome Text', you may need to double the backslash. Otherwise, your dialect of sed may not recognize \t as tab.
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| Jul 20, 2016 at 20:37 | comment | added | Terrance | The echo line works perfect for DD-WRT firmware for a script I run. Using sed and putting in the \t for a tab, puts just a t then the next part. Where the echo line actually puts the tab in instead of the t. Thank you! | |
| Oct 23, 2015 at 16:33 | comment | added | Dennis Williamson |
@Kira: The 1 means do the next command only on line one of the file and the i command is insert. Look in the man page under the "Addresses" section and in the "Zero- or One- address commands" section.
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| Oct 22, 2015 at 19:04 | comment | added | Kira | I didn't know about this possible syntax in sed's last example, can someone tell me what is the name of this type of syntax so I can search more about it? | |
| Aug 22, 2015 at 19:28 | comment | added | Dennis Williamson |
@onaclov2000: The second sed command in my answer says to insert a line of text before line 1. I'd have to see the command you used to know why it inserted it on every other line. You probably omitted the address (1).
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| Aug 22, 2015 at 17:15 | comment | added | onaclov2000 | Using the third option, I got the task in the file every other line....so I guess it put it on the first line, but didn't do so well for the rest of the file for my use case. | |
| Aug 5, 2014 at 10:14 | comment | added | SF. |
cat can be freely used to concatenate binaries. Note how split and join do entirely different things; cat is the companion to split, not join. And that means, if your cat messed up \n your implementation is horribly broken.
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| Jan 27, 2014 at 15:24 | comment | added | Felix | Using 2 and 3 (3 seems simpler to me) allows you to prepend text to many files at once. | |
| Jan 26, 2014 at 21:58 | comment | added | Dennis Williamson |
@itaifrenkel: I'd have to see what you did, but if cat receives a literal backslash n, it won't convert it to a newline. Something else must have done that. Instead of cat, try piping into hexdump -C to see if you're actually sending backslash and n or if it's a newline. You could also try cat -e to show line endings.
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| Jan 26, 2014 at 21:37 | comment | added | itaifrenkel | Instead of printing \n it may print a newline. Happened to me. Used the sed version just fine instead | |
| Jan 26, 2014 at 12:16 | comment | added | Dennis Williamson | @itaifrenkel: In what way? | |
| Jan 26, 2014 at 8:50 | comment | added | itaifrenkel | cat could be a problem if cat encounters \n | |
| Feb 18, 2011 at 4:51 | comment | added | Dennis Williamson |
@user8347: Pipe (|) the message (echo '...') to cat which uses - (standard input) as the first file and todo.txt as the second. cat conCATenates multiple files. Send the output (>) to a file named temp. If there are no errors (&&) from cat then rename (mv) the temp file back to the original file (todo.txt).
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| Feb 18, 2011 at 4:24 | vote | accept | user479534 | ||
| Feb 18, 2011 at 4:24 | comment | added | user479534 | the first one works great! would you mind explaining the logic? im not particularly sure how to interpret the syntax. | |
| Feb 17, 2011 at 3:34 | history | answered | Dennis Williamson | CC BY-SA 2.5 |