Getting real argv[0] in python

[Stuart D. Gathman]

On Tue, 28 Oct 2003 13:52:26 -0500, Stuart D. Gathman wrote:

> I need to be able to obtain the real argv[0] (not the script name).
> The application is writing a CUPS backend in python.  For some reason,
> CUPS decided to pass the URI as argv[0] (perhaps to ensure that CUPS
> will only ever run on Unix, since CUPS stands for Common *Unix*
> Printing System).  The only solution I can think of is to write a C 
> wrapper that inserts the original argv[0] before execing python with
> the script.
> 
> Is there already a way to do this that I have missed?

Here is the simple C wrapper I am using:

#include <stdio.h>
#include <string.h>
#include <unistd.h>

static const char scriptdir[] = "/usr/lib/cups/python/";

int main(int argc,char **argv) {
  char *nargv[10];
  char script[256];
  const char *p;
  int i;
  int slen,len;
  if (argc > 7) {
    fputs("Usage: pycups uri ...",stderr);
    return 1;
  }

  p = strchr(argv[0],':');
  if (p)
    len = p - argv[0];
  else
    len = strlen(argv[0]);
  slen = strlen(scriptdir);
  strcpy(script,scriptdir);
  if (len + slen + 4 > sizeof script)
    len = sizeof script - slen - 4;
  strncat(script,argv[0],len);
  script[slen + len] = 0;
  strcat(script,".py");

  nargv[0] = "python2";
  nargv[1] = script;
  for (i = 0; i < argc; ++i)
    nargv[i+2] = argv[i];
  nargv[i+2] = 0;
  execvp("python2",nargv);
  perror("exec");
  return 1;
}

-- 
	      Stuart D. Gathman <stuart at bmsi.com>
Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flamis acribus addictis" - background song for
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