How do I make rm not give an error if a file doesn't exist?

347

33

I'm writing a makefile that will clean up some useless files at the end of the compilation. If a target has already been made, it will of course skip that target and the useless file may not be there. So if I do this:

rm lexer.ml interpparse.ml interpparse.mli

I may get errors because one of the files doesn't exist. Is there any way to tell rm to ignore these files?

In reading the man page, I see the following option:

 -f          Attempt to remove the files without prompting for confirma-
             tion, regardless of the file's permissions.  If the file does
             not exist, do not display a diagnostic message or modify the
             exit status to reflect an error.  The -f option overrides any
             previous -i options.

That sounds like almost what I want, but I'm not really sure about the permissions part. Is there a way to do this?

Jason Baker

Posted 2009-11-27T16:43:23.687

Reputation: 6 382

just for completeness: there is rm --interactive=never which acts like rm -f except it does return an error exit status. see here for more details: https://unix.stackexchange.com/questions/72864/how-to-avoid-the-need-to-issue-y-several-times-when-removing-protected-file/438486#438486

– lesmana – 2019-04-08T07:11:34.133

Since you mentioned Makefile in the question, I think @robertLi's answer suits the best. Prepending with '-' is a make way of doing this; others dealing with Makefiles will likely recognise it. – akauppi – 2019-11-27T13:34:36.020

If the permissions won't allow it, rm will with the -f option still try to delete it. It will fail. It won't tell you it failed. Useful if the filename is a variable or a glob. – LawrenceC – 2012-06-13T01:24:56.070

Did you try some rm in a sandbox? It looks like -f does exactly what you want, regardless of the globbing. – JMD – 2009-11-27T17:02:06.193

Answers

296

The -f option is definitely what you want to be using.

The confirmation about file permissions it refers to is this:

$ touch myfile    
$ chmod 400 myfile
$ rm myfile       
rm: remove write-protected regular empty file `myfile'?

So rm will warn you if you try to delete a file you don't have write permissions on. This is allowed if you have write permissions on the directory but is a little weird, which is why rm normally warns you about it.

Dave Webb

Posted 2009-11-27T16:43:23.687

Reputation: 10 126

1

If you want the error message, but not the error exit code, see the answer by Giel Berkers. I use set -e in all my bash scripts so that the script exits after any command gives an error. I often want a script to tell me if rm gave an error, but continue anyway. continues.

– cledoux – 2016-06-06T04:05:42.893

1Most, but not all systems will ask (I think). Some require -i. – DaveParillo – 2009-11-27T18:11:57.673

132

Another solution is this one: https://stackoverflow.com/questions/11231937/bash-ignoring-error-for-a-particular-command

Just add an OR-statement after your command:

rm -rf my/dir || true

This way, when statement #1 fails (throws error), run statement #2, which is simply true.

Giel Berkers

Posted 2009-11-27T16:43:23.687

Reputation: 1 429

4It prints the error and continues the execution, which was desired for my case. – worldsayshi – 2016-02-29T14:28:18.810

9Or just rm -rf my/dir ||: to be even more concise (: is short for true) – Godsmith – 2016-10-04T14:55:03.850

The better solution in my opinion. It's easily visible what's happening and why the result code is ignored. I like it! – Mavamaarten – 2017-10-03T14:13:47.737

79

I'm way late to the party, but I use this all the time. In a makefile, add - to the beginning of a line to ignore the return value of that line. Like so:

-rm lexer.ml interpparse.ml interpparse.mli

Robert Li

Posted 2009-11-27T16:43:23.687

Reputation: 899

9This will still print error to the console though, which trains you to ignore errors in the make output, which is probably not what you want. rm -rf is a better option in my opinion. – Godsmith – 2016-10-04T14:54:05.447

@Godsmith I'd rather ignore an error than forcing recursive delete. This could be very naughty. And +1 for the makefile specific syntax – Daishi – 2017-12-06T15:06:07.887

If rm -rf could be "naughty", it means that you are using make outside a directory under version control. Why? – Godsmith – 2017-12-08T07:27:14.930

Give a link to documentation, please. Could find description of this feature. – George Sovetov – 2018-01-30T16:50:31.487

@GeorgeSovetov https://www.gnu.org/software/make/manual/make.html#Errors

– Robert Li – 2018-01-30T20:45:49.713

1I think this is superior. -f also skips interactive mode, skips readonly files etc. - this solution however does exactly what OP asked for. – phil294 – 2018-03-17T06:39:05.260

14

If you don't want to use the -f option, an alternative is:

rm filethatdoesntexist 2> /dev/null 

This will just keep errors from being printed.

user135299

Posted 2009-11-27T16:43:23.687

Reputation: 141

9Unfortunately this will still give an error exit code. – Shaun McDonald – 2013-11-20T17:37:13.897

8

If you find some way to glob the file names, rm won't complain if it can't find a match. So something like lexer.m* interpparse.*, etc. should work for you (be careful you're not deleting too much, of course). Also, -f is a perfectly reasonable way to go, as long as you're not hoping that file permissions will save you from deleting a file you didn't want to - if you don't want to delete it, don't put it in the list.

Nick Bastin

Posted 2009-11-27T16:43:23.687

Reputation: 367

The globbing would be out of the question as there is a lexer.mll file that I don't want to delete. Thanks for showing why -f is reasonable. I suppose I tend to be overly careful after one too many misguided sudo rm -rf . – Jason Baker – 2009-11-27T16:53:07.317

Not even a more restrictive lexer.m? ...? That would catch lexer.ml and lexer.mz, but not lexer.mll or lexer.mla. – JMD – 2009-11-27T16:58:54.700

1@JMD: I suppose it depends on your shell and what pattern-matching support it offers for globbing. – Nick Bastin – 2009-11-29T00:56:04.910

6

The -f option means that you will not be prompted if something is not as expected. It does not mean that permissions are not taken into account.

If you have not enough privileges to remove a file, it won't be removed.

BUT, if you have enough privileges to change privileges, you file will be removed. This is the case when you are the owner of a file with readonly permissions for owner (-r--------). As owner, you can chmod u+w, then remove it: rm -f will remove that file.

mouviciel

Posted 2009-11-27T16:43:23.687

Reputation: 2 858

5

Maybe could help a line similar with:

touch fakefile.exe fakefile.o && rm *.o *.exe

I know that this is not very smart, but it does the job.

Bogdan

Posted 2009-11-27T16:43:23.687

Reputation: 51

3

An alternative:

RmIfIsFile() {  for f in "$@"; do [ -f $f ] && rm $f; done; };  RmIfIsFile lexer.ml interpparse.ml interpparse.mli

Too bad Makefiles can't share shell function definitions across lines.

reinierpost

Posted 2009-11-27T16:43:23.687

Reputation: 1 904

Have you tried to use \ (backslash) at the end of a row to let it continue on the next? – some – 2012-07-31T19:35:04.290

@some: Yes, they can be spread across multiple lines, but to share them across recipes you have to put the definition in a make variable. – reinierpost – 2012-10-01T13:56:49.660

3

Here's what I use in shell scripts. It hides the error message and error code.

rm doesnotexist 2> /dev/null || echo > /dev/null

teh_senaus

Posted 2009-11-27T16:43:23.687

Reputation: 141

how about rm doesnotexist 2&> /dev/null – user8162 – 2019-02-18T23:07:29.140

2

test to see if the file exists first, if it does, then pass it to rm. Then the errors from rm will be meaningful. -f or ignoring the error message is typically more encompassing than what a person wants. -f might do things you don't want done.

if [ -f lexer.ml ]; then
  rm lexer.ml
fi

add more test clauses if there are more files you want to be sure exist.

user337861

Posted 2009-11-27T16:43:23.687

Reputation:

1

you can touch the files before you rm them. that would create them if they don't exist :-)

touch lexer.ml interpparse.ml interpparse.mli
rm lexer.ml interpparse.ml interpparse.mli

commonpike

Posted 2009-11-27T16:43:23.687

Reputation: 293

1

write rm -rf ppp>/dev/null 2>&1 you newer get error message Problem occurs, if error generate not to STDERR 2 but STDOUT 1... It's take place when command generate not error but warning. You need to set filter and remove this message. But this case is ordinary.

Anatoly

Posted 2009-11-27T16:43:23.687

Reputation: 11