I'm a careless terminal driver scared of accidentally deleting files, hence using some aliases like alias rm='rm -i' for rm, mv, cp. How can I get a similar confirmation behavior for file redirections (e.g echo "I'm silly" > very_important_file.txt).
The common case is that I usually use replace (>) instead of append (>>) and so I ended up accidentally deleting some mid-important files. What are your suggestions?
I don't think there's a way to get the exact behavior of -i, but I have noclobber set which prevents overwriting already existing files.
See this page for a usage example.
You can try out the command like this (and if you like it, include it in your startup file)
$ set -o noclobber
Example:
$ ls > ls.out
$ set -o noclobber
$ ls > ls.out
bash: ls.out: cannot overwrite existing file
$
Update:
As @jsbillings mentions in a helpful comment below, to override the noclobber in bash one can use >|
Since I primarily use tcsh (a csh variant), the override operator is >!
noclobber set, and you do want to clobber the file without having to change settings, bash has a >| redirect that ignores the noclobber setting.
Commented
Aug 17, 2012 at 18:29
csh/tcsh override would be using >!
csh/tcsh
-ioptions and settingnoclobberare temporary workarounds, but use them with caution - if they just encourage you to be more careless you'll run into trouble the day one of those settings gets reset or you have to use someone else's system. If you plan to spend any non-trivial amount of time in the terminal, a better protection is to train yourself to think about what you are doing before you press the enter key. I've learned my lessons from accidental terminal goofs, but most of them were not serious because I had backups.noclobberorcp -iis irresponsible.-iandnoclobberare nothing like seatbelts because they change the way basic commands work, whereas fastening a seatbelt doesn't cause your car to refuse to go into reverse or ask for confirmation every time you step on the accelerator. (... continued ...)-iwhen appropriate, and never assume that the system has it aliased, nor do I advocate getting into the habit of assuming so. The way I see it, blindly assuming the car will fasten your seatbelt for you (or the system hasnoclobberset) is much more irresponsible.