[Toybox] [TOY] lspci

[Georgi Chorbadzhiyski]

On 7/22/13 10:05 PM, Felix Janda wrote:
> Isaac wrote:
>>
>> I've written an lspci implementation.
> 
> Cool.
> 
>> Currently it supports -emkn; -e is an extension ("class" is a 24-bit number,
>> but lspci only shows 16 bits; one person on the Puppy forums mentioned
>> that they need those last 8 bits).
>> -n is a no-op for compatability with standard lspci.
> 
> Are there any more options you have in mind that should be implemented?
> Just out of curiosity: Could you post a link to the forum post?
> 
>> 75 lines total.
> 
> Down to 70 after application of the below patch with small fixes.
> 
> It felt more sensible to me to read 2 more bytes and ignore them than to
> seek for 2 bytes in a file. So preadat_name now has one argument less.
> 
> Use calloc instead of malloc + memset. With this also the off-by-one
> error from (origninally) line 32 is fixed. It would be nice to use
> toybuf for this, wouldn't it? That would also make valgrind happier.
> 
> Print "" instead of "." when .../driver is missing.
> 
> The only difference between the usual output and the machine readable
> output is the format string. Use this to avoid some repetition.
> 
> Felix
> 
> --- a/lspci.c	2013-07-22 18:05:37.514838360 +0200
> +++ b/lspci.c	2013-07-22 19:12:03.000000000 +0200
> @@ -17,19 +17,14 @@
>  */
>  #define FOR_lspci
>  #include "toys.h"
> -char * preadat_name(int dirfd, char *fname, size_t nbyte, off_t offset)
> +char * preadat_name(int dirfd, char *fname, size_t nbyte)
>  {
>    int fd;
> -  char *buf = malloc(nbyte+1);
> -  memset(buf, 0, sizeof(buf));
> -  fd = openat(dirfd, fname, O_RDONLY);
> -  if (fd < 0) {
> -    return NULL;
> -  }
> -  lseek(fd, offset, SEEK_SET);
> +  char *buf = calloc(1, nbyte+1);
> +
> +  if (0 > (fd = openat(dirfd, fname, O_RDONLY))) return NULL;

It would be better to move calloc after openat (which may fail).

-- 
Georgi Chorbadzhiyski
http://georgi.unixsol.org/
http://github.com/gfto/