lib/vlog: clarify usage of vmodule and vpath flag
It's currently hard to use these flags correctly without some
trial-and-error or looking at the implementation of the llog package.
Among points of confusion:
- whether the .go extension is part of the matched string
- what kind of pattern is expected (glob, regexp)
- whether a full match or partial match is required
This CL spells out the pattern type, and the omission of the .go
suffix. It also offers positive and negative examples since that's the
more concise and understandable way to illustrate the usage.
MultiPart: 1/2
Change-Id: Ia0f58bc07d4d2efcdfe4155954110b49fc4f1eaa
diff --git a/vlog/flags.go b/vlog/flags.go
index 83fc1d7..a2b5775 100644
--- a/vlog/flags.go
+++ b/vlog/flags.go
@@ -36,8 +36,8 @@
{"max_stack_buf_size", &maxStackBufSize, 4192 * 1024, "max size in bytes of the buffer to use for logging stack traces"},
{"v", &verbosity, nil, "log level for V logs"},
{"stderrthreshold", &stderrThreshold, nil, "logs at or above this threshold go to stderr"},
- {"vmodule", &vmodule, nil, "comma-separated list of pattern=N settings for filename-filtered logging"},
- {"vpath", &vpath, nil, "comma-separated list of pattern=N settings for file pathname-filtered logging"},
+ {"vmodule", &vmodule, nil, "comma-separated list of globpattern=N settings for filename-filtered logging (without the .go suffix). E.g. foo/bar/baz.go is matched by patterns baz or *az or b* but not by bar/baz or baz.go or az or b.*"},
+ {"vpath", &vpath, nil, "comma-separated list of regexppattern=N settings for file pathname-filtered logging (without the .go suffix). E.g. foo/bar/baz.go is matched by patterns foo/bar/baz or fo.*az or oo/ba or b.z but not by foo/bar/baz.go or fo*az"},
{"log_backtrace_at", &traceLocation, nil, "when logging hits line file:N, emit a stack trace"},
}
