cuserid.c raw

   1  #define _GNU_SOURCE
   2  #include <pwd.h>
   3  #include <stdio.h>
   4  #include <unistd.h>
   5  #include <string.h>
   6  
   7  char *cuserid(char *buf)
   8  {
   9  	static char usridbuf[L_cuserid];
  10  	struct passwd pw, *ppw;
  11  	long pwb[256];
  12  	if (buf) *buf = 0;
  13  	getpwuid_r(geteuid(), &pw, (void *)pwb, sizeof pwb, &ppw);
  14  	if (!ppw)
  15  		return buf;
  16  	size_t len = strnlen(pw.pw_name, L_cuserid);
  17  	if (len == L_cuserid)
  18  		return buf;
  19  	if (!buf) buf = usridbuf;
  20  	memcpy(buf, pw.pw_name, len+1);
  21  	return buf;
  22  }
  23