xbps-uhelper: add verbose output for cmpver/pkgmatch

I can never remember which retval means which thing. This only prints if
-v/--verbose is specified.

Examples:
```
$ ./bin/xbps-uhelper/xbps-uhelper -v cmpver 1 2 ; echo ret: $?
1 < 2
ret: 255
$ ./bin/xbps-uhelper/xbps-uhelper -v cmpver 1 1 ; echo ret: $?
1 = 1
ret: 0
$ ./bin/xbps-uhelper/xbps-uhelper -v cmpver 2 1 ; echo ret: $?
2 > 1
ret: 1
$ ./bin/xbps-uhelper/xbps-uhelper -v pkgmatch 'foo-1.0_1' 'foo>=0' ; echo ret: $?
foo-1.0_1 matches foo>=0
ret: 1
$ ./bin/xbps-uhelper/xbps-uhelper -v pkgmatch 'foo-1.0_1' 'foo<0.1_1' ; echo ret: $?
foo-1.0_1 does not match foo<0.1_1
ret: 0
```

it also seems that getting an error from pkgmatch is currently impossible

bin/xbps-uhelper/main.c

@@ -46,6 +46,7 @@ usage(void)
 	    " -C --config <dir>                    Path to confdir (xbps.d)\n"
 	    " -d --debug                           Debug mode shown to stderr\n"
 	    " -r --rootdir <dir>                   Full path to rootdir\n"
+	    " -v --verbose                         Verbose messages\n"
 	    " -V --version                         Show XBPS verison\n"
 	    "\n"
 	    "MODE\n"
@@ -96,11 +97,12 @@ main(int argc, char **argv)
 		{ "config", required_argument, NULL, 'C' },
 		{ "debug", no_argument, NULL, 'd' },
 		{ "rootdir", required_argument, NULL, 'r' },
+		{ "verbose", no_argument, NULL, 'v' },
 		{ "version", no_argument, NULL, 'V' },
 		{ NULL, 0, NULL, 0 }
 	};
 
-	while ((c = getopt_long(argc, argv, "C:dr:V", longopts, NULL)) != -1) {
+	while ((c = getopt_long(argc, argv, "C:dr:vV", longopts, NULL)) != -1) {
 		switch (c) {
 		case 'C':
 			confdir = optarg;
@@ -112,6 +114,9 @@ main(int argc, char **argv)
 		case 'd':
 			flags |= XBPS_FLAG_DEBUG;
 			break;
+		case 'v':
+			flags |= XBPS_FLAG_VERBOSE;
+			break;
 		case 'V':
 			printf("%s\n", XBPS_RELVER);
 			exit(EXIT_SUCCESS);
@@ -318,14 +323,29 @@ main(int argc, char **argv)
 		/* Matches a pkg with a pattern */
 		if (argc != 3)
 			usage();
-
-		exit(xbps_pkgpattern_match(argv[1], argv[2]));
+		rv = xbps_pkgpattern_match(argv[1], argv[2]);
+		if (flags & XBPS_FLAG_VERBOSE) {
+			if (rv >= 0)
+				fprintf(stderr, "%s %s %s\n",
+					argv[1],
+					(rv == 1) ? "matches" : "does not match",
+					argv[2]);
+			else
+				xbps_error_printf("%s: not a pattern\n", argv[2]);
+		}
+		exit(rv);
 	} else if (strcmp(argv[0], "cmpver") == 0) {
 		/* Compare two version strings, installed vs required */
 		if (argc != 3)
 			usage();
 
-		exit(xbps_cmpver(argv[1], argv[2]));
+		rv = xbps_cmpver(argv[1], argv[2]);
+		if (flags & XBPS_FLAG_VERBOSE)
+			fprintf(stderr, "%s %s %s\n",
+				argv[1],
+				(rv == 1) ? ">" : ((rv == 0) ? "=" : "<"),
+				argv[2]);
+		exit(rv);
 	} else if (strcmp(argv[0], "arch") == 0) {
 		/* returns the xbps native arch */
 		if (argc != 1)

bin/xbps-uhelper/xbps-uhelper.1

@@ -59,6 +59,8 @@ Enables extra debugging shown to stderr.
 Show the help message.
 .It Fl r, Fl -rootdir Ar dir
 Specifies a full path for the target root directory.
+.It Fl v, Fl -verbose
+Enables verbose messages.
 .It Fl V, Fl -version
 Show the version information.
 .El
@@ -85,6 +87,14 @@ strings,
 See
 .Sx EXIT STATUS
 for more information.
+If
+.Fl -verbose
+is specified, also prints
+.Qo
+.Ar instver
+<|=|>
+.Ar reqver
+.Qc .
 .It Cm getname Ar string ...
 Prints the pkgname of
 .Ar pkgpatterns
@@ -126,6 +136,15 @@ with a
 See
 .Sx EXIT STATUS
 for more information.
+If
+.Fl -verbose
+is specified, also prints
+.Qo
+.Ar pkgver
+matches|does not match
+.Ar pkgpattern
+.Qc ,
+or an error.
 .It Cm real-version Ar pkgname ...
 Prints the version of installed real packages.
 .It Cm version Ar pkgname ...

data/_xbps

@@ -229,10 +229,7 @@ _xbps_uchroot() {
 _xbps_uhelper() {
 	local ret=1
 	_arguments \
-		{-C,--config=-}'[Full path to configuration file]:config file:_files' \
-		{-d,--debug}'[Debug mode shown to stderr]' \
-		{-r,--rootdir=-}'[Full path to rootdir]:root dir:_files -/' \
-		{-V,--version}'[Show XBPS version]' \
+		$_xbps_common \
 		'1:action:->actions' \
 		'*:: :->args' && ret=0
 	case $state in