mjhjmtu

I'm trying to run the following command:

find a/folder b/folder -name *.c -o -name *.h -exec grep -I foobar '' +

This is returning an error:

find: missing argument to -exec

I can't see what's wrong with this command, as it seems to match the man page:

-exec command +

This variant of the -exec option runs the specified command on
the selected files, but the command line is built by appending
each selected file name at the end; the total number of invoca-
tions of the command will be much less than the number of
matched files. The command line is built in much the same way
that xargs builds its command lines. Only one instance of ''
is allowed within the command. The command is executed in the
starting directory.

I also tried:

find a/folder b/folder -name *.c -o -name *.h -exec grep -I foobar +
find a/folder b/folder -name *.c -o -name *.h -exec 'grep -I foobar' +
find a/folder b/folder -name *.c -o -name *.h -exec 'grep -I foobar' '' +
find a/folder b/folder -name "*.c" -o -name "*.h" -exec grep -I foobar '' +
find a/folder b/folder ( -name *.c -o -name *.h ) -exec grep -I foobar '' +
find a/folder b/folder -name *.c -o -name *.h -exec grep -I foobar '' +

You need to remove the backticks you use around . The command can be simplified like this:

find a/folder b/folder -name "*.[ch]" -exec grep -I foobar +

Should you use an archaic GNU find version, this should still work:

find a/folder b/folder -name "*.[ch]" -exec grep -I foobar ;

“missing argument to -exec” usually means that the argument to -exec is missing its terminator. The terminator must either be an argument containing just the character ; (which needs to be quoted in a shell command, so it's typically written ; or ';'), or two successive arguments containing and +.

Stephane Chazelas has identified that you're using an older version of GNU find which doesn't support -exec … +, only -exec ;. Although GNU was a late adopter of -exec … +, I do recommend that you get a less antique tool suite (such as Cygwin, which includes git and a whole lot more, or GNUwin32, which lacks git but doesn't have the bad-employee-trying-to-use-linux-but-we-impose-windows vibe that Cygwin gives). This feature was added in version 4.2.12, over 9 years ago (it was the last identified feature to make GNU find POSIX-compliant).

If you want to stick to an older GNU find, you can use -print0 with xargs -0 to get a similar functionality: grouped command execution, supporting arbitrary file names.

find a/folder b/folder -name '*.c' -o -name '*.h' -print0 | xargs -0 grep -I foobar /dev/null

Always quote the wildcards on the find command line. Otherwise, if you happen to run this command from a directory containing .c files, the unquoted *.c would be expanded to the list of .c files in the current directory.

Adding /dev/null to the grep command line is a trick to ensure that grep will always print the file name, even if find happens to find a single match. With GNU find, another method is to pass the option -H.

when I was using like following way

"$sudo find . -type f -perm 0777 -exec chmod 644 ;"

then I was getting this error "find: missing argument to `-exec' "

when I did bit space between '' and ''. It got fixed .

"sudo find . -type f -perm 0777 -print -exec chmod 644 ;"

I had my share of headaches with the exec syntax in the past. most days now I prefer the nicer bash syntax:

for f in `find a/folder b/folder -name "*.[ch]"`; do grep -I foobar $f; done

It has some limitations when you want to treat the files as a group, as each is evaluated serially, but you can pipe the output elsewhere just fine