[RFC] Get selection to buffer addition

salvador
2001-07-31T16:33:32Z

Hi all:

I'm sending this mail again with the patch in plain text and not
gzip+uuencoded, sorry for any inconvenience.

What I'm looking for:
I'm looking for comments and approval for a small addition to the console
driver (drivers/char/console.c).

Small description:
The included patches adds a couple of new services to the TIOCLINUX ioctl
call, they are:

13 (get selection into a buffer): It copies the contents of the selection
buffer (maintained in kernel space) into a user space provided buffer. Is
something like "paste to a buffer" instead of just paste to the current
console.

14 (get selection length): Returns the length of the selection buffer (0 if
none selected).
-----------

The included file contains diffs that apply
without offsets into 2.4.7 kernel, they are valid for 2.2.18 too (with
offset).
I also include a simple test program that calls the new services. The test
program is really simple and assumes you can open /dev/tty1 (you are
there or you are root ;-)

Additional question: Why the switch uses numbers? Shouldn't these values be
defined as something like TIOCLINUX_GET_SELECTION in a header?

What's the purpose? Just allow pasting in text editors using menues or
without the mouse middle button and avoiding to missinterpret the pasted
text as keystrokes.

SET

Patch (about 77 lines):
-------------------------------------------
--- linux-2.4.7.orig/drivers/char/console.c Tue Jun 12 15:17:17 2001
+++ linux-2.4.7/drivers/char/console.c Thu Jul 26 17:33:46 2001
@@ -14,6 +14,8 @@
*
* Copy and paste function by Andrew Haylett,
* some enhancements by Alessandro Rubini.
+ * get selection into a buffer and length by
+ * Salvador E. Tropea <salvador@inti.gov.ar>
*
* Code to check for different video-cards mostly by Galen Hunt,
* <g-hunt@ee.utah.edu>
@@ -2204,6 +2206,10 @@
return 0;
case 12: /* get fg_console */
return fg_console;
+ case 13: /* get selection into a buffer */
+ return get_selection_buffer(arg);
+ case 14: /* get selection length */
+ return put_user(get_selection_length(), (unsigned int
*)((char *)arg + 1));
}
return -EINVAL;
}
--- linux-2.4.7.orig/drivers/char/selection.c Fri Feb 9 16:30:22 2001
+++ linux-2.4.7/drivers/char/selection.c Thu Jul 26 17:53:46 2001
@@ -288,6 +288,41 @@
return 0;
}

+/* Copy the contents of the selection buffer into a
+ * user space buffer.
+ * Invoked by ioctl().
+ */
+int get_selection_buffer(const unsigned long arg)
+{
+ char *dest;
+ unsigned int length;
+
+ if (get_user(length, (unsigned int *)(arg + sizeof(char))))
+ return -EFAULT;
+
+ dest = (char *)(arg + sizeof(char) + sizeof(unsigned int));
+
+ if (length > sel_buffer_lth)
+ length = sel_buffer_lth;
+
+ if (sel_buffer) {
+ if (copy_to_user(dest, sel_buffer, length))
+ return -EFAULT;
+ } else {
+ length = 0;
+ }
+ __put_user(length, (unsigned long *)(arg + sizeof(char)));
+ return 0;
+}
+
+/* Get the selection buffer length.
+ * Invoked by ioctl().
+ */
+unsigned int get_selection_length(void)
+{
+ return sel_buffer ? sel_buffer_lth : 0;
+}
+
/* Insert the contents of the selection buffer into the
* queue of the tty associated with the current console.
* Invoked by ioctl().
--- linux-2.4.7.orig/include/linux/selection.h Fri Jul 20 16:53:56 2001
+++ linux-2.4.7/include/linux/selection.h Thu Jul 26 17:40:07 2001
@@ -17,6 +17,8 @@
extern int sel_loadlut(const unsigned long arg);
extern int mouse_reporting(void);
extern void mouse_report(struct tty_struct * tty, int butt, int mrx, int
mry);
+extern int get_selection_buffer(const unsigned long arg);
+extern unsigned int get_selection_length(void);

#define video_num_columns (vc_cons[currcons].d->vc_cols)
#define video_num_lines (vc_cons[currcons].d->vc_rows)
-------------------------------------------
End of patch.

Test program:
-------------------------------------------
#include <stdio.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>

int main(int argc, char *argv[])
{
int i,res,fd,largo;
char buffer[sizeof(unsigned int)+2],*s;
unsigned int *lg=(unsigned int *)(buffer+1);

fd=open("/dev/tty1",O_RDWR);

printf("Finding the length of the selection:\n");
buffer[0]=14;
res=ioctl(fd,TIOCLINUX,&buffer);
printf("The iotcl returns %d\n",res);
printf("Length: %u\n",*lg);
largo=*lg;
if (*lg==0) return 0;

printf("Asking for the selection:\n");
s=(char *)malloc(largo+sizeof(unsigned int)+2);
s[0]=13;
lg=(unsigned int *)(s+1);
*lg=largo;
res=ioctl(fd,TIOCLINUX,s);
printf("The iotcl returns %d\n",res);
largo=*lg;
printf("Length returned: %d\n",largo);
s+=1+sizeof(unsigned int);
s[largo]=0;

for (i=0; s[i]; i++)
if (s[i]==13) s[i]=10;
printf("Selection: '%s' (%d)\n",s,s[0]);
return 0;
}