Enhance feedback of missing argument to -exec

[Karl-Philipp Richter]

Invoking a wrong `find` command, e.g. `find . -name pom.xml -exec grep '<repository>' {}+` causes the error message `find: missing argument to `-exec'` which could be more helpful if the error message would reflect the correct usage, e.g `find: missing argument to `-exec <arg> {}+'`.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: findutils 4.4.2-9
Uname: Linux 3.19.0-031900-generic x86_64
ApportVersion: 2.14.7-0ubuntu8.1
Architecture: amd64
CurrentDesktop: Unity
Date: Mon Feb 16 19:28:45 2015
Dependencies:
 gcc-4.9-base 4.9.1-16ubuntu6
 libc6 2.19-10ubuntu2.2
 libgcc1 1:4.9.1-16ubuntu6
 multiarch-support 2.19-10ubuntu2.2
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-01-26 (20 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
SourcePackage: findutils
UpgradeStatus: No upgrade log present (probably fresh install)

[Stefan Wagner (wagner-stefan)]

Did you notice, that you need a blank before the plus sign?

$ find . -name pom.xml -exec grep '<repository>' {}+
$ find . -name pom.xml -exec grep '<repository>' {} +

For example, if find finds the files a/pom.xml and b/pom.xml, it will try to build the exec part as:

$ grep '<repository>' a/pom.xml b/pom.xml+

instead of

$ grep '<repository>' a/pom.xml b/pom.xml

leaving the + for find as special option.

[Karl-Philipp Richter (krichter722)]

Whatever is wrong, `find: missing argument to `-exec'` doesn't really help if `find` could just explain what's wrong.