logcat: Note in help that regexps are Perl-compatible
The expressions accepted by the '-e'/'--grep' command line option are
PCRE:
https://android.googlesource.com/platform/system/core/+/master/logcat/logcat.cpp#1018
Say so in the help string.
Change-Id: I7f6af130d5e39570bb49310a928f5d495e5b269b
diff --git a/logcat/logcat.cpp b/logcat/logcat.cpp
index 07981fc..a2aa486 100644
--- a/logcat/logcat.cpp
+++ b/logcat/logcat.cpp
@@ -457,7 +457,7 @@
" -d Dump the log and then exit (don't block)\n"
" -e <expr>, --regex=<expr>\n"
" Only print lines where the log message matches <expr>\n"
- " where <expr> is a regular expression\n"
+ " where <expr> is a Perl-compatible regular expression\n"
// Leave --head undocumented as alias for -m
" -m <count>, --max-count=<count>\n"
" Quit after printing <count> lines. This is meant to be\n"
