Re: gawk 3.1.0 getgroups problem

[Aharon Robbins]

Greetings.  Re this:

> Date: Mon, 3 Dec 2001 01:06:26 -0800
> From: "John H. DuBois III" <address@hidden>
> To: address@hidden
> Subject: gawk 3.1.0 getgroups problem
>
> Under SCO OpenServer 5.0.6a using gawk 3.1.0 compiled with gcc 2.95.2, if a
> process has more than 8 supplemental groups, any reference to PROCINFO[] 
> gives:
>
> $ gawk 'BEGIN{print PROCINFO["pid"]}'
> gawk: cmd. line:1: fatal: could not find groups: Invalid argument
>
> This is because gawk is using getgroups(8):
>
> getgroups(8, 134508692) = EINVAL
>
> The most common approach for determining the size of the array to pass to
> getgroups is to first check how many groups the process is in:
>
> getgroups(0, 0) = 18
> malloc...
> getgroups(18, 134559144) = 18
>
>       John
> --
> John DuBois  address@hidden  KC6QKZ/AE  http://www.armory.com./~spcecdt/

The following unofficial patch does the trick.

Arnold Robbins
---------------------------------------------------------
diff -cr gawk-3.1.1/awk.h gawk-sco-test/awk.h
*** gawk-3.1.1/awk.h    Sun Nov  4 10:50:26 2001
--- gawk-sco-test/awk.h Mon Dec  3 13:59:37 2001
***************
*** 648,653 ****
--- 648,658 ----
  extern int in_end_rule;
  extern int whiny_users;
  
+ #if defined (HAVE_GETGROUPS) && defined(NGROUPS_MAX) && NGROUPS_MAX > 0
+ extern GETGROUPS_T *groupset;
+ extern int ngroups;
+ #endif
+ 
  extern const char *myname;
  
  extern char quote;
diff -cr gawk-3.1.1/configure gawk-sco-test/configure
*** gawk-3.1.1/configure        Tue Nov 13 17:28:52 2001
--- gawk-sco-test/configure     Mon Dec  3 13:58:00 2001
***************
*** 5113,5119 ****
    echo "$ac_t""no" 1>&6
  fi
  
! for ac_func in memset memcpy memcmp fmod setlocale strchr strerror \
                 strftime strncasecmp strtod system tzset
  do
  echo $ac_n "checking for $ac_func""... $ac_c" 1>&6
--- 5113,5119 ----
    echo "$ac_t""no" 1>&6
  fi
  
! for ac_func in getgroups memset memcpy memcmp fmod setlocale strchr strerror \
                 strftime strncasecmp strtod system tzset
  do
  echo $ac_n "checking for $ac_func""... $ac_c" 1>&6
diff -cr gawk-3.1.1/configure.in gawk-sco-test/configure.in
*** gawk-3.1.1/configure.in     Tue Nov 13 17:28:48 2001
--- gawk-sco-test/configure.in  Mon Dec  3 13:47:05 2001
***************
*** 128,134 ****
  esac
  
  AC_CHECK_LIB(m, fmod)
! AC_CHECK_FUNCS(memset memcpy memcmp fmod setlocale strchr strerror \
                 strftime strncasecmp strtod system tzset)
  
  dnl check for dynamic linking
--- 128,134 ----
  esac
  
  AC_CHECK_LIB(m, fmod)
! AC_CHECK_FUNCS(getgroups memset memcpy memcmp fmod setlocale strchr strerror \
                 strftime strncasecmp strtod system tzset)
  
  dnl check for dynamic linking
diff -cr gawk-3.1.1/io.c gawk-sco-test/io.c
*** gawk-3.1.1/io.c     Sun Nov  4 10:50:48 2001
--- gawk-sco-test/io.c  Mon Dec  3 13:57:28 2001
***************
*** 1351,1360 ****
  {
        char tbuf[BUFSIZ], *cp;
        int i;
- #if defined(NGROUPS_MAX) && NGROUPS_MAX > 0
-       GETGROUPS_T groupset[NGROUPS_MAX];
-       int ngroups;
- #endif
  
        warning(_("use `PROCINFO[...]' instead of `/dev/user'"));
  
--- 1351,1356 ----
***************
*** 1362,1371 ****
  
        cp = tbuf + strlen(tbuf);
  #if defined(NGROUPS_MAX) && NGROUPS_MAX > 0
-       ngroups = getgroups(NGROUPS_MAX, groupset);
-       if (ngroups == -1)
-               fatal(_("could not find groups: %s"), strerror(errno));
- 
        for (i = 0; i < ngroups; i++) {
                *cp++ = ' ';
                sprintf(cp, "%d", (int) groupset[i]);
--- 1358,1363 ----
diff -cr gawk-3.1.1/main.c gawk-sco-test/main.c
*** gawk-3.1.1/main.c   Thu Aug 30 15:17:04 2001
--- gawk-sco-test/main.c        Mon Dec  3 13:59:15 2001
***************
*** 54,59 ****
--- 54,60 ----
  static void nostalgia P((void));
  static void version P((void));
  static void init_fds P((void));
+ static void init_groupset P((void));
  
  /* These nodes store all the special variables AWK uses */
  NODE *ARGC_node, *ARGIND_node, *ARGV_node, *BINMODE_node, *CONVFMT_node;
***************
*** 125,130 ****
--- 126,136 ----
  
  extern char *version_string;  /* current version, for printing */
  
+ #if defined (HAVE_GETGROUPS) && defined(NGROUPS_MAX) && NGROUPS_MAX > 0
+ GETGROUPS_T *groupset;                /* current group set */
+ int ngroups;                  /* size of said set */
+ #endif
+ 
  /* The parse tree is stored here.  */
  NODE *expression_value;
  
***************
*** 242,247 ****
--- 248,256 ----
        /* Robustness: check that 0, 1, 2, exist */
        init_fds();
  
+       /* load group set */
+       init_groupset();
+ 
        /* worst case */
        emalloc(srcfiles, struct src *, argc * sizeof(struct src), "main");
        memset(srcfiles, '\0', argc * sizeof(struct src));
***************
*** 777,786 ****
        NODE **aptr;
        char name[100];
        AWKNUM value;
- #if defined(NGROUPS_MAX) && NGROUPS_MAX > 0
-       GETGROUPS_T groupset[NGROUPS_MAX];
-       int ngroups;
- #endif
  
        PROCINFO_node = install("PROCINFO",
                        node(Nnull_string, Node_var, (NODE *) NULL));
--- 786,791 ----
***************
*** 828,838 ****
        aptr = assoc_lookup(PROCINFO_node, tmp_string("FS", 2), FALSE);
        *aptr = make_string("FS", 2);
  
! #if defined(NGROUPS_MAX) && NGROUPS_MAX > 0
!       ngroups = getgroups(NGROUPS_MAX, groupset);
!       if (ngroups == -1)
!               fatal(_("could not find groups: %s"), strerror(errno));
! 
        for (i = 0; i < ngroups; i++) {
                sprintf(name, "group%d", i + 1);
                value = groupset[i];
--- 833,839 ----
        aptr = assoc_lookup(PROCINFO_node, tmp_string("FS", 2), FALSE);
        *aptr = make_string("FS", 2);
  
! #if defined (HAVE_GETGROUPS) && defined(NGROUPS_MAX) && NGROUPS_MAX > 0
        for (i = 0; i < ngroups; i++) {
                sprintf(name, "group%d", i + 1);
                value = groupset[i];
***************
*** 1005,1008 ****
--- 1006,1034 ----
  #endif
                }
        }
+ }
+ 
+ /* init_groupset --- initialize groupset */
+ 
+ static void
+ init_groupset()
+ {
+ #if defined(HAVE_GETGROUPS) && defined(NGROUPS_MAX) && NGROUPS_MAX > 0
+       /*
+        * If called with 0 for both args, return value is
+        * total number of groups.
+        */
+       ngroups = getgroups(0, NULL);
+       if (ngroups == -1)
+               fatal(_("could not find groups: %s"), strerror(errno));
+       else if (ngroups == 0)
+               return;
+ 
+       /* fill in groups */
+       emalloc(groupset, GETGROUPS_T *, ngroups * sizeof(GETGROUPS_T), 
"init_groupset");
+ 
+       ngroups = getgroups(ngroups, groupset);
+       if (ngroups == -1)
+               fatal(_("could not find groups: %s"), strerror(errno));
+ #endif
  }