[udev] make udev user callable to query the database (experimental)

[udev] make udev user callable to query the database (experimental)

[Kay Sievers]

[-- Attachment #1: Type: text/plain, Size: 467 bytes --]

Here is a patch that makes it possible to call udev with options on the command line.
Valid options are for now:

-V for the udev version:
    kay@pim:~/src/udev.kay$ ./udev -V
    udev, version 011_bk

-r for the udev root:
    kay@pim:~/src/udev.kay$ ./udev -r
    /udev/

-q to query the database with the sysfs path for the name of the node:
    kay@pim:~/src/udev.kay$ ./udev -q /class/video4linux/video0
    test/video/webcam0


What do you think?

thanks,
Kay

[-- Attachment #2: 02-make-udev-user-callable.diff --]
[-- Type: text/plain, Size: 3081 bytes --]

diff -Nru a/udev.c b/udev.c
--- a/udev.c	Tue Dec 30 05:11:30 2003
+++ b/udev.c	Tue Dec 30 05:11:30 2003
@@ -29,6 +29,7 @@
 #include <errno.h>
 #include <ctype.h>
 #include <signal.h>
+#include <stdarg.h>
 
 #include "udev.h"
 #include "udev_version.h"
@@ -81,22 +82,58 @@
 	return seqnum;
 }
 
-int main(int argc, char **argv, char **envp)
+static inline int udev_user(int argc, char **argv)
 {
-	char *action;
-	char *devpath;
-	char *subsystem;
+	static const char short_options[] = "q:rV";
+	int option;
 	int retval = -EINVAL;
+	struct udevice dev;
 
-	main_argv = argv;
-	main_envp = envp;
+	while (1) {
+		option = getopt(argc, argv, short_options);
+		if (option == -1)
+			break;
 
-	dbg("version %s", UDEV_VERSION);
+		dbg("option '%c'", option);
+		switch (option) {
+		case 'q':
+			dbg("udev query: %s\n", optarg);
+			retval = udevdb_open_ro();
+			if (retval != 0) {
+				printf("unable to open udev database\n");
+				return -1;
+			}
+			retval = udevdb_get_dev(optarg, &dev);
+			if (retval == 0) {
+				printf("%s\n", dev.name);
+			} else {
+				printf("device not found in udev database\n");
+			}
+			udevdb_exit();
+			return retval;
 
-	if (argc != 2) {
-		dbg ("unknown number of arguments");
-		goto exit;
+		case 'r':
+			printf("%s\n", udev_root);
+			return 0;
+
+		case 'V':
+			printf("udev, version %s\n", UDEV_VERSION);
+			return 0;
+
+		default:
+			printf("unknown option '%c'\n", option);
+			return -1;
+		}
 	}
+	return retval;
+}
+
+static inline int udev_hotplug(int argc, char **argv)
+{
+	char *action;
+	char *devpath;
+	char *subsystem;
+	int retval = -EINVAL;
 
 	subsystem = argv[1];
 
@@ -126,9 +163,6 @@
 		goto exit;
 	}
 
-	/* initialize our configuration */
-	udev_init_config();
-
 	/* connect to the system message bus */
 	sysbus_connect();
 
@@ -166,3 +200,27 @@
 exit:
 	return retval;
 }
+
+int main(int argc, char **argv, char **envp)
+{
+	main_argv = argv;
+	main_envp = envp;
+	int retval;
+
+	dbg("version %s", UDEV_VERSION);
+
+	/* initialize our configuration */
+	udev_init_config();
+
+	if (argc == 2 && argv[1][0] != '-') {
+		dbg("called by hotplug");
+		retval = udev_hotplug(argc, argv);
+	} else {
+		dbg("called by user");
+		retval = udev_user(argc, argv);
+	}
+
+	return retval;
+}
+
+
diff -Nru a/udevdb.c b/udevdb.c
--- a/udevdb.c	Tue Dec 30 05:11:30 2003
+++ b/udevdb.c	Tue Dec 30 05:11:30 2003
@@ -128,3 +128,16 @@
 	}
 	return 0;
 }
+
+/**
+ * udevdb_init: open database for reading
+ */
+int udevdb_open_ro(void)
+{
+	udevdb = tdb_open(udev_db_filename, 0, 0, O_RDONLY, 0);
+	if (udevdb == NULL) {
+		dbg("unable to open database at '%s'", udev_db_filename);
+		return -EINVAL;
+	}
+	return 0;
+}
diff -Nru a/udevdb.h b/udevdb.h
--- a/udevdb.h	Tue Dec 30 05:11:30 2003
+++ b/udevdb.h	Tue Dec 30 05:11:30 2003
@@ -11,6 +11,7 @@
 /* function prototypes */
 extern void udevdb_exit(void);
 extern int udevdb_init(int init_flag);
+extern int udevdb_open_ro(void);
 
 extern int udevdb_add_dev(const char *path, const struct udevice *dev);
 extern int udevdb_get_dev(const char *path, struct udevice *dev);

Re: [udev] make udev user callable to query the database (experimental)

[Kay Sievers]

[-- Attachment #1: Type: text/plain, Size: 778 bytes --]

Here is a slightly better version that prints the usage if a unknown option is given:
  kay@pim:~/src/udev.kay$ ./udev -x
  ./udev: invalid option -- x
  Usage: [-qrVh]
    -q arg     query database 
    -r         print udev root
    -V         print udev version
    -h         print this help text


thanks,
Kay

> Here is a patch that makes it possible to call udev with options on the command line.
> Valid options are for now:
> 
> -V for the udev version:
>     kay@pim:~/src/udev.kay$ ./udev -V
>     udev, version 011_bk
> 
> -r for the udev root:
>     kay@pim:~/src/udev.kay$ ./udev -r
>     /udev/
> 
> -q to query the database with the sysfs path for the name of the node:
>     kay@pim:~/src/udev.kay$ ./udev -q /class/video4linux/video0
>     test/video/webcam0


[-- Attachment #2: 02-make-udev-user-callable.diff --]
[-- Type: text/plain, Size: 3337 bytes --]

diff -Nru a/udev.c b/udev.c
--- a/udev.c	Tue Dec 30 14:04:03 2003
+++ b/udev.c	Tue Dec 30 14:04:03 2003
@@ -29,6 +29,7 @@
 #include <errno.h>
 #include <ctype.h>
 #include <signal.h>
+#include <stdarg.h>
 
 #include "udev.h"
 #include "udev_version.h"
@@ -81,23 +82,70 @@
 	return seqnum;
 }
 
-int main(int argc, char **argv, char **envp)
+static inline int udev_user(int argc, char **argv)
 {
-	char *action;
-	char *devpath;
-	char *subsystem;
+	static const char short_options[] = "q:rVh";
+	int option;
 	int retval = -EINVAL;
+	struct udevice dev;
 
-	main_argv = argv;
-	main_envp = envp;
+	while (1) {
+		option = getopt(argc, argv, short_options);
+		if (option == -1)
+			break;
 
-	dbg("version %s", UDEV_VERSION);
+		dbg("option '%c'", option);
+		switch (option) {
+		case 'q':
+			dbg("udev query: %s\n", optarg);
+			retval = udevdb_open_ro();
+			if (retval != 0) {
+				printf("unable to open udev database\n");
+				return -1;
+			}
+			retval = udevdb_get_dev(optarg, &dev);
+			if (retval == 0) {
+				printf("%s\n", dev.name);
+			} else {
+				printf("device not found in udev database\n");
+			}
+			udevdb_exit();
+			return retval;
 
-	if (argc != 2) {
-		dbg ("unknown number of arguments");
-		goto exit;
+		case 'r':
+			printf("%s\n", udev_root);
+			return 0;
+
+		case 'V':
+			printf("udev, version %s\n", UDEV_VERSION);
+			return 0;
+
+		case 'h':
+			retval = 0;
+		case '?':
+		default:
+			goto help;
+		}
 	}
 
+help:
+	printf("Usage: [-qrVh]\n"
+	       "  -q arg     query database \n"
+	       "  -r         print udev root\n"
+	       "  -V         print udev version\n"
+	       "  -h         print this help text\n"
+	       "\n");
+
+	return retval;
+}
+
+static inline int udev_hotplug(int argc, char **argv)
+{
+	char *action;
+	char *devpath;
+	char *subsystem;
+	int retval = -EINVAL;
+
 	subsystem = argv[1];
 
 	devpath = get_devpath();
@@ -126,9 +174,6 @@
 		goto exit;
 	}
 
-	/* initialize our configuration */
-	udev_init_config();
-
 	/* connect to the system message bus */
 	sysbus_connect();
 
@@ -166,3 +211,27 @@
 exit:
 	return retval;
 }
+
+int main(int argc, char **argv, char **envp)
+{
+	main_argv = argv;
+	main_envp = envp;
+	int retval;
+
+	dbg("version %s", UDEV_VERSION);
+
+	/* initialize our configuration */
+	udev_init_config();
+
+	if (argc == 2 && argv[1][0] != '-') {
+		dbg("called by hotplug");
+		retval = udev_hotplug(argc, argv);
+	} else {
+		dbg("called by user");
+		retval = udev_user(argc, argv);
+	}
+
+	return retval;
+}
+
+
diff -Nru a/udevdb.c b/udevdb.c
--- a/udevdb.c	Tue Dec 30 14:04:03 2003
+++ b/udevdb.c	Tue Dec 30 14:04:03 2003
@@ -128,3 +128,16 @@
 	}
 	return 0;
 }
+
+/**
+ * udevdb_init: open database for reading
+ */
+int udevdb_open_ro(void)
+{
+	udevdb = tdb_open(udev_db_filename, 0, 0, O_RDONLY, 0);
+	if (udevdb == NULL) {
+		dbg("unable to open database at '%s'", udev_db_filename);
+		return -EINVAL;
+	}
+	return 0;
+}
diff -Nru a/udevdb.h b/udevdb.h
--- a/udevdb.h	Tue Dec 30 14:04:03 2003
+++ b/udevdb.h	Tue Dec 30 14:04:03 2003
@@ -11,6 +11,7 @@
 /* function prototypes */
 extern void udevdb_exit(void);
 extern int udevdb_init(int init_flag);
+extern int udevdb_open_ro(void);
 
 extern int udevdb_add_dev(const char *path, const struct udevice *dev);
 extern int udevdb_get_dev(const char *path, struct udevice *dev);

Re: [udev] make udev user callable to query the database (experimental)

[Greg KH]

On Tue, Dec 30, 2003 at 02:13:26PM +0100, Kay Sievers wrote:
> Here is a slightly better version that prints the usage if a unknown option is given:
>   kay@pim:~/src/udev.kay$ ./udev -x
>   ./udev: invalid option -- x
>   Usage: [-qrVh]
>     -q arg     query database 
>     -r         print udev root
>     -V         print udev version
>     -h         print this help text

Nice, I like this.  It's a great start to the query capabilities.

Applied.

thanks,

greg k-h


-------------------------------------------------------
This SF.net email is sponsored by: IBM Linux Tutorials.
Become an expert in LINUX or just sharpen your skills.  Sign up for IBM's
Free Linux Tutorials.  Learn everything from the bash shell to sys admin.
Click now! http://ads.osdn.com/?ad_id\x1278&alloc_id371&op=click
_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel