I'm using Mac OS X. I'm trying to copying some files with cp command for a build script like this.
cp ./src/*/*.h ./aaa
But this command fires an error if there is no .h file in ./src directory. How to make the command don't fire the error? (silent failure) The error makes build result fail, but I just want to copy when only there are some header file.
If you're talking about the error message, you can suppress that by sending it to the bit bucket:
cp ./src/*/*.h ./aaa 2>/dev/null
If you want to suppress the exit code and the error message:
cp ./src/*/*.h ./aaa 2>/dev/null || :
You're looking for something along the lines of
if [ -e file ]
then cp file /somewhere
fi
(Unfortunately, the -f option is not the droid you're looking for.)
If you want to match a glob, that won't work; use find instead, e.g.:
find ./src -name \*.h -exec cp {} ./destination \;
Piping the result to true ensures that the command will always succeed. I have tried this on Linux but not on any Mac OS:
cp ./src/*/*.h ./aaa | true
Old question, but might still be relevant for others.
If you don't need to use cp, you could try with rsync.
To copy all files from a source to a destination directory, run:
rsync -avzh --ignore-errors /path/to/source /path/to/destination
Rsync comes with most Unix-like systems such as Linux, Mac OS X or FreeBSD.
You could force the correct error status. With a function:
$ cpalways () { cp $1 $2 2>/dev/null ; return 0 ; }
Given the following:
$ ls foo bar baz
ls: baz: No such file or directory
bar foo
Regular copy will return an error. It will return an exit status of 1.
$ cp baz bar ; echo $?
cp: baz: No such file or directory
1
If we use the cpalways() function above, any errors will be hidden:
$ cpalways baz bar ; echo $?
0
$ cpalways foo bar ; echo $?
0
$ cpalways baz bar ; echo $?
0
