Date: Thu, 17 May 2001 14:52:09 +0300 From: Ruslan Ermilov <ru@FreeBSD.ORG> To: Nik Clayton <nik@FreeBSD.ORG> Cc: arch@FreeBSD.ORG Subject: Re: [PATCH] syscons ioctl() to grab text mode buffer Message-ID: <20010517145209.C55371@sunbay.com> In-Reply-To: <20010517121902.A3047@catkin.nothing-going-on.org>; from nik@FreeBSD.ORG on Thu, May 17, 2001 at 12:19:02PM %2B0100 References: <20010517121902.A3047@catkin.nothing-going-on.org>
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On Thu, May 17, 2001 at 12:19:02PM +0100, Nik Clayton wrote:
> Two things for review.
>
[...]
> The second, scrshot.c uses the ioctl to dump the contents of the video
> memory to stdout. Usage is
>
> scrshot /dev/ttyv0 > shot.scr
>
There are some style(9) and -security issues with this:
--- scrshot.c~ Thu May 17 14:42:40 2001
+++ scrshot.c Thu May 17 14:50:22 2001
@@ -28,9 +28,9 @@
* $FreeBSD$
*/
+#include <sys/types.h>
#include <sys/consio.h>
#include <sys/ioctl.h>
-#include <sys/types.h>
#include <sys/uio.h>
#include <err.h>
@@ -48,7 +48,6 @@
main(int argc, char *argv[])
{
int fd;
- int result;
scrshot_t shot;
vid_info_t info;
@@ -56,33 +55,24 @@
errx(1, "improper # of args");
fd = open(argv[1], O_RDWR);
- if (fd < 0) {
- perror(argv[1]);
- exit(1);
- }
+ if (fd < 0)
+ err(1, "%s", argv[1]);
info.size = sizeof(info);
- result = ioctl(fd, CONS_GETINFO, &info);
- if (result != 0) {
- perror("getinfo failed");
- exit(1);
- }
+ if (ioctl(fd, CONS_GETINFO, &info) == -1)
+ err(1, "ioctl(CONS_GETINFO)");
shot.buf = malloc(info.mv_csz * info.mv_rsz * sizeof(u_int16_t));
- if (!shot.buf) {
- perror("couldn't allocate shot space");
- exit(1);
- }
+ if (shot.buf == NULL)
+ err(1, "couldn't allocate shot space");
shot.xsize = info.mv_csz;
shot.ysize = info.mv_rsz;
- result = ioctl (fd, CONS_SCRSHOT, &shot);
- if (result != 0) {
- perror("CONS_SCRSHOT failed");
- exit(1);
- }
+ if (ioctl(fd, CONS_SCRSHOT, &shot) == -1)
+ err(1, "ioctl(CONS_SCRSHOT)");
- write(1, shot.buf, shot.xsize * shot.ysize * sizeof(u_int16_t));
+ (void) write(STDOUT_FILENO, shot.buf,
+ shot.xsize * shot.ysize * sizeof(u_int16_t));
- return 0;
+ exit(0);
}
Cheers,
--
Ruslan Ermilov Oracle Developer/DBA,
ru@sunbay.com Sunbay Software AG,
ru@FreeBSD.org FreeBSD committer,
+380.652.512.251 Simferopol, Ukraine
http://www.FreeBSD.org The Power To Serve
http://www.oracle.com Enabling The Information Age
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