Document -C/-D

* strace.c (usage): Document -C.
* strace.1: Document -D.

strace.1

@@ -43,7 +43,7 @@ strace \- trace system calls and signals
 .SH SYNOPSIS
 .B strace
 [
-.B \-CdffhiqrtttTvxx
+.B \-CdDffhiqrtttTvxx
 ]
 [
 .BI \-a column
@@ -84,6 +84,9 @@ strace \- trace system calls and signals
 .B strace
 .B \-c
 [
+.B \-D
+]
+[
 .BI \-e expr
 ]
 \&...
@@ -255,6 +258,13 @@ Like
 .B \-c
 but also print regular output while processes are running.
 .TP
+.B \-D
+(Not available on SVR4 and FreeBSD.)
+Run tracer process as a detached grandchild, not as parent of the
+tracee.  This reduces the visible effect of
+.B strace
+by keeping the tracee a direct child of the calling process.
+.TP
 .B \-d
 Show some debugging output of
 .B strace

strace.c

@@ -168,12 +168,13 @@ FILE *ofp;
 int exitval;
 {
 	fprintf(ofp, "\
-usage: strace [-dffhiqrtttTvVxx] [-a column] [-e expr] ... [-o file]\n\
+usage: strace [-CdDffhiqrtttTvVxx] [-a column] [-e expr] ... [-o file]\n\
               [-p pid] ... [-s strsize] [-u username] [-E var=val] ...\n\
               [command [arg ...]]\n\
-   or: strace -c -D [-e expr] ... [-O overhead] [-S sortby] [-E var=val] ...\n\
+   or: strace -c [-D] [-e expr] ... [-O overhead] [-S sortby] [-E var=val] ...\n\
               [command [arg ...]]\n\
 -c -- count time, calls, and errors for each syscall and report summary\n\
+-C -- like -c but also print regular output while processes are running\n\
 -f -- follow forks, -ff -- with output into separate files\n\
 -F -- attempt to follow vforks, -h -- print help message\n\
 -i -- print instruction pointer at time of syscall\n\
@@ -746,7 +747,6 @@ main(int argc, char *argv[])
 			debug++;
 			break;
 #ifndef USE_PROCFS
-		/* Experimental, not documented in manpage yet. */
 		case 'D':
 			daemonized_tracer = 1;
 			break;