text: #include "sysutil.h"
  #include <string.h>
  
  int env_argc = 0;
  char **env_argv = NULL;
  
  static const char *find_key(const char *params, const char *key);
  
  /*===========================================================================*
   *				env_setargs				     *
   *===========================================================================*/
  void env_setargs(int arg_c, char *arg_v[])
  {
  	env_argc= arg_c;
  	env_argv= arg_v;
  }
  
  /*===========================================================================*
   *				env_get_param				     *
   *===========================================================================*/
  int env_get_param(const char *key, char *value, int max_len)
  {
    message m;
    static char mon_params[MULTIBOOT_PARAM_BUF_SIZE]; /* copy parameters here */
    const char *key_value;
    int i, s;
    size_t keylen;
  
    if (key == NULL)
    	return EINVAL;
  
    keylen= strlen(key);
    for (i= 1; i<env_argc; i++)
    {
    	if (strncmp(env_argv[i], key, keylen) != 0)
    		continue;
  	if (strlen(env_argv[i]) <= keylen)
  		continue;
  	if (env_argv[i][keylen] != '=')
  		continue;
  	key_value= env_argv[i]+keylen+1;
  	if (strlen(key_value)+1 > (size_t) max_len)
  	      return(E2BIG);
  	strcpy(value, key_value);
  	return OK;
    }
  
    /* Get copy of boot monitor parameters. */
    m.m_type = SYS_GETINFO;
    m.m_lsys_krn_sys_getinfo.request = GET_MONPARAMS;
    m.m_lsys_krn_sys_getinfo.endpt = SELF;
    m.m_lsys_krn_sys_getinfo.val_len = sizeof(mon_params);
    m.m_lsys_krn_sys_getinfo.val_ptr = (vir_bytes)mon_params;
    if ((s=_kernel_call(SYS_GETINFO, &m)) != OK) {
  	printf("SYS_GETINFO: %d (size %zu)\n", s, sizeof(mon_params));
  	return(s);
    }
  
    /* We got a copy, now search requested key. */
    if ((key_value = find_key(mon_params, key)) == NULL)
  	return(ESRCH);
  
    /* Value found, see if it fits in the client's buffer. Callers assume that
     * their buffer is unchanged on error, so don't make a partial copy.
     */
    if ((strlen(key_value)+1) > (size_t) max_len) return(E2BIG);
  
    /* Make the actual copy. */
    strcpy(value, key_value);
  
    return(OK);
  }
  
  
  /*==========================================================================*
   *				find_key				    *
   *==========================================================================*/
  static const char *find_key(const char *params, const char *name)
  {
    const char *namep, *envp;
  
    for (envp = params; *envp != 0;) {
  	for (namep = name; *namep != 0 && *namep == *envp; namep++, envp++)
  		;
  	if (*namep == '\0' && *envp == '=') 
  		return(envp + 1);
  	while (*envp++ != 0)
  		;
    }
    return(NULL);
  }
  
  