1 files changed, 99 insertions, 0 deletions
diff --git a/libc/pwd/__getpwent.c b/libc/pwd/__getpwent.c
new file mode 100644
index 0000000..9836ca7
--- /dev/null
+++ b/libc/pwd/__getpwent.c
@@ -0,0 +1,99 @@
+/*
+ * __getpwent.c - This file is part of the libc-8086/pwd package for ELKS,
+ * Copyright (C) 1995, 1996 Nat Friedman <ndf@linux.mit.edu>.
+ * 
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Library General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Library General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Library General Public
+ *  License along with this library; if not, write to the Free
+ *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <pwd.h>
+
+#define PWD_BUFFER_SIZE 256
+
+/* This isn't as flash as my previous version -- it doesn't dynamically
+  scale down the gecos on too-long lines, but it also makes fewer syscalls,
+  so it's probably nicer.  Write me if you want the old version.  Maybe I
+  should include it as a build-time option... ?
+  -Nat <ndf@linux.mit.edu> */
+   
+struct passwd *
+__getpwent(int pwd_fd)
+{
+  static char line_buff[PWD_BUFFER_SIZE];
+  static struct passwd passwd;
+  char * field_begin;
+  char * endptr;
+  char * gid_ptr;
+  char * uid_ptr;
+  int line_len;
+  int i;
+
+  /* We use the restart label to handle malformatted lines */
+restart:
+  /* Read the passwd line into the static buffer using a minimal of
+     syscalls. */
+  if ((line_len=read(pwd_fd, line_buff, PWD_BUFFER_SIZE))<=0)
+    return NULL;
+  field_begin=strchr(line_buff, '\n');
+  if (field_begin!=NULL)
+    lseek(pwd_fd, (long) (1+field_begin-(line_buff+line_len)), SEEK_CUR);
+  else /* The line is too long - skip it. :-\ */
+    {
+      do { if ((line_len=read(pwd_fd, line_buff, PWD_BUFFER_SIZE))<=0)
+	return NULL;
+      } while (!(field_begin=strchr(line_buff, '\n')));
+      lseek(pwd_fd, (long) (field_begin-line_buff)-line_len+1, SEEK_CUR);
+      goto restart;
+    }
+  if (*line_buff=='#' || *line_buff==' ' || *line_buff=='\n' ||
+      *line_buff=='\t')
+      goto restart;
+  *field_begin='\0';
+
+  /* We've read the line; now parse it. */
+  field_begin=line_buff;
+  for (i=0;i<7;i++)
+    {
+      switch(i)
+	{
+	case 0: passwd.pw_name=field_begin; break;
+	case 1: passwd.pw_passwd=field_begin; break;
+	case 2: uid_ptr=field_begin; break;
+	case 3: gid_ptr=field_begin; break;
+	case 4: passwd.pw_gecos=field_begin; break;
+	case 5: passwd.pw_dir=field_begin; break;
+	case 6: passwd.pw_shell=field_begin; break;
+	}
+      if (i<6)
+	{
+	  field_begin=strchr(field_begin, ':');
+	  if (field_begin==NULL) goto restart;
+	  *field_begin++='\0';
+	}
+    }
+  passwd.pw_gid=(gid_t) strtoul(gid_ptr, &endptr, 10);
+  if (*endptr!='\0') goto restart;
+  
+  passwd.pw_uid=(uid_t) strtoul(uid_ptr, &endptr, 10);
+  if (*endptr!='\0') goto restart;
+
+  return &passwd;
+}
+
+