🚀 go-pugleaf

Subject: getusershell() is buggy
Index:	lib/libc/gen/getusershell.c 4.3BSD

Description:
	Getusershell(3) does not handle comments correctly.  Setusershell(3)
	does not work at all.
Repeat-By:
	Run the following program with the default version of /etc/shells.
	Notice that the first shell printed out is /passwd.  This comes
	from one of the leading comments in the file /etc/shells.  Also notice
	that setusershell() does not rewind the shells file so nothing is
	printed out in the second loop.

main() {
	char *cp, *getusershell();

	for (cp = getusershell(); cp; cp = getusershell())
		printf("%s\n", cp);
	setusershell();
	for (cp = getusershell(); cp; cp = getusershell())
		printf("%s\n", cp);
}

Fix:
	There was a fix posted as 4573@brl-smoke.ARPA to netnews.
	That fix (as received at my site) was obviously incorrect since
	it didn't work and it contained a line of code that looked like:

	while (!isspace(*cp) != '/' && *cp != '\0')

	Here is a context diff (to the original getusershell.c) to fix
	the problem.

*** getusershell.c.old	Mon Oct 27 17:17:05 1986
--- getusershell.c.new	Mon Oct 27 17:17:05 1986
***************
*** 58,64 ****
  setusershell()
  {
  
! 	shells = initshells();
  }
  
  static char **
--- 58,64 ----
  setusershell()
  {
  
! 	endusershell();
  }
  
  static char **
***************
*** 96,101 ****
--- 96,103 ----
  	sp = shells;
  	cp = strings;
  	while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) {
+ 		if (*cp == '#')
+ 			continue;
  		while (*cp != '/' && *cp != '\0')
  			cp++;
  		if (*cp == '\0')