That has nothing to do with adb. That's just not the option you're looking for
. The option you're thinking of is -v, which will show non matching lines, rather than matching lines. A very common use of that would be if you're looking for a particular process. You would type something like:
ps -ef|grep process
The problem is that grep itself is a process, and shows up in the output, generally, so it's usually removed by doing this:
pe -ef|grep -v grep|grep process
The option you used, -L, is the opposite of the -l option, which suppresses normal output (the matched line) and shows the input file where the matched line was found. It can only be used effectively when input is from a file rather than stdin (where stdin is standard input). When you use a command like this:
command|command
the input to that second command is called standard input. That is what the -L is going to look at, and it's quite useless here. When you use grep like this:
grep -l pattern file
where pattern is the pattern you're looking for in a particular file, you can use -L. Of course, it's just going to return with the name of the file instead of the line, which is also useless here, but it becomes useful when you give multiple files for input. This is most useful when you do something like this:
grep -l pattern *
What that will do is search all files matched by * (all files in the current directory) for the pattern, and display a list of files where the pattern was found. You can use whatever expression you like, too (file*, for example, for all files that start with "file"). You were you using -L, so that would be the opposite. If you did:
grep -L pattern *
it would return with a list of files where the pattern was *not* found.
Once you start getting into the command line more, you'll realize just how powerful this sort of thing is when used with either the find command and the exec option, or the xargs command. I'll give you an exmaple:
find /some/path -type f -exec grep -l pattern {} \;
That will search (find) for all files (-type f) under /some/path, and all its subdirectories, then run (exec) whatever command you give after exec, which in this case is grep. So it will grep for your pattern on all files found in the directory structure under /some/path. The {} is a placeholder for input and is basically the list returned by find. Basically, this command is used to dump a list of files that contain your pattern. It's different from grep -l pattern * in that the find command will search the whole path structure you give rather than just the current directory.
Does that answer your question?
