Added locking function and interface

Added mbox_header_line
Added mbox_body_lines

-/* copyright and license info go here */
+/* GNU mailutils - a suite of utilities for electronic mail
+   Copyright (C) 1999 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
 #include "mailbox.h"
 #include "unixmbox.h"
@@ -40,6 +55,7 @@ mbox_open (const char *name)
   mbox->_expunge = _mbox_dummy1;
   mbox->_add_message = _mbox_dummy3;
   mbox->_is_deleted = _mbox_dummy2;
+  mbox->_lock = _mbox_dummy2;
   mbox->_get_body = _mbox_dummy4;
   mbox->_get_header = _mbox_dummy4;
 
@@ -68,6 +84,97 @@ mbox_open (const char *name)
 }
 
 /*
+ * Gets the contents of a header field
+ */
+char *
+mbox_header_line (mailbox *mbox, int num, const char *header)
+{
+  char *full, *tmp, *line;
+  int i = 0, j=0, try = 1, len;
+  int lh = strlen (header);
+  full = mbox_get_header (mbox, num);
+  if (full == NULL)
+    return NULL;
+ 
+  len = strlen (full);
+
+  /* First get the appropriate line at the beginning */
+  for (i=0; i < len-(lh+2); i++)
+    {
+      if (try == 1)
+	{
+	  if (!strncasecmp(&full[i], header, lh) && full[i+lh] == ':')
+	    {
+	      full[len-i] = '\0';
+	      tmp = strdup (&full[i+lh+2]);
+	      i = len;
+	    }
+	  else
+	    try = 0;
+	}
+      else if (full[i] == '\n')
+	try = 1;
+      else
+	try = 0;
+    }
+
+  /* Now trim the fat */
+  len = strlen (tmp);
+  for (i = 0; i < len; i++)
+    {
+      if (tmp[i] == '\n' && i < (len - 1) && (tmp[i+1] == ' ' || tmp[i+1] == '\t'))
+	{
+	  if (tmp[i+1] == '\t')
+	    tmp[i + 1] = ' ';
+	  for (j = i; j < len; j++)
+	    tmp[j] = tmp[j+1];
+	}
+      else if (tmp[i] == '\n')
+	{
+	  tmp[i] = '\0';
+	  i = len;
+	}
+    }
+  line = strdup (tmp);
+  free (tmp);
+  free (full);
+  return line;
+}
+
+/*
+ * Gets first LINES lines from message body
+ */
+char *
+mbox_body_lines (mailbox *mbox, int num, int lines)
+{
+  char *full, *buf = NULL;
+  int i=0, line = 0, len;
+  if (lines < 1)
+    return strdup ("");
+  full = mbox_get_body (mbox, num);
+  if (full == NULL)
+    return NULL;
+  len = strlen (full);
+  for (i=0; i < len && line < lines; i++)
+    {
+      if (full[i] == '\n')
+	{
+	  line++;
+	  if (line >= lines)
+	    {
+	      full[i+1] = '\0';
+	      buf = strdup (full);
+	      i = len;
+	    }
+	}
+    }
+  if (buf == NULL)
+    buf = strdup (full);
+  free (full);
+  return buf;
+}
+
+/*
  * Bogus functions for unimplemented functions that return int
  */
 int
@@ -97,3 +204,4 @@ _mbox_dummy4 (mailbox * mbox, int num)
   errno = ENOSYS;
   return NULL;
 }
+

-/* copyright and license info go here */
+/* GNU mailutils - a suite of utilities for electronic mail
+   Copyright (C) 1999 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
 #ifndef _MAILBOX_H
 #define _MAILBOX_H	1
@@ -20,6 +35,12 @@
 #define mbox_add_message(m,s)	m->_add_message(m,s)
 #define mbox_get_body(m,n)	m->_get_body(m,n)
 #define mbox_get_header(m,n)	m->_get_header(m,n)
+#define mbox_lock(m,n)		m->_lock(m,n)
+
+/* Lock settings */
+#define MO_ULOCK	0
+#define MO_RLOCK	1
+#define MO_WLOCK	2
 
 typedef struct _mailbox
   {
@@ -37,6 +58,7 @@ typedef struct _mailbox
     int (*_expunge) __P ((struct _mailbox *));
     int (*_add_message) __P ((struct _mailbox *, char *));
     int (*_is_deleted) __P ((struct _mailbox *, int));
+    int (*_lock) __P((struct _mailbox *, int));
     char *(*_get_body) __P ((struct _mailbox *, int));
     char *(*_get_header) __P ((struct _mailbox *, int));
   }
@@ -44,4 +66,9 @@ mailbox;
 
 mailbox *mbox_open __P ((const char *name));
 
+char *mbox_header_line __P ((mailbox *mbox, int num, const char *header));
+char *mbox_body_lines __P ((mailbox *mbox, int num, int lines));
+
 #endif
+
+

-/* copyright and license info go here */
+/* GNU mailutils - a suite of utilities for electronic mail
+   Copyright (C) 1999 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
 #include "unixmbox.h"
 
 /*
- * Opens and locks a mailbox
+ * Opens a mailbox
  */
 int
 unixmbox_open (mailbox * mbox)
@@ -22,7 +37,6 @@ unixmbox_open (mailbox * mbox)
 
   mbox->_data = data;
   data->file = fopen (mbox->name, "r+");
-  /* FIXME: do a good, NFS safe, file lock here, with error handling */
   if (data->file == NULL)
     {
       /* errno is set by fopen() */
@@ -39,6 +53,17 @@ unixmbox_open (mailbox * mbox)
       return -1;
     }
 
+  fgets (buf, 80, data->file);
+  if (strncmp (buf, "From ", 5))
+    {
+      /* This is NOT an mbox file */
+      unixmbox_close (mbox);
+      errno = 0;
+      return -1;
+    }
+  else
+    rewind (data->file);
+
   while (fgets (buf, 80, data->file))
     {
       if (!strncmp (buf, "From ", 5))
@@ -88,6 +113,7 @@ unixmbox_open (mailbox * mbox)
   mbox->_expunge = unixmbox_expunge;
   mbox->_add_message = unixmbox_add_message;
   mbox->_is_deleted = unixmbox_is_deleted;
+  mbox->_lock = unixmbox_lock;
   mbox->_get_body = unixmbox_get_body;
   mbox->_get_header = unixmbox_get_header;
 
@@ -101,7 +127,7 @@ int
 unixmbox_close (mailbox * mbox)
 {
   unixmbox_data *data = mbox->_data;
-  /* FIXME: good file unlocking, to go along with the locking above */
+  unixmbox_lock (mbox, MO_ULOCK);
   fclose (data->file);
   free (data->messages);
   free (mbox->sizes);
@@ -266,3 +292,17 @@ unixmbox_get_header (mailbox * mbox, int num)
   fread (buf, size, sizeof (char), data->file);
   return buf;
 }
+
+/*
+ * Sets lock mode for a mailbox
+ * FIXME: this doesn't do anything, really
+ * Get locking code from Procmail and/or Exim
+ */
+int
+unixmbox_lock (mailbox *mbox, int mode)
+{
+  unixmbox_data *data = mbox->_data;
+  data->lockmode = mode;
+  return 0;
+}
+

-/* copyright and license info go here */
+/* GNU mailutils - a suite of utilities for electronic mail
+   Copyright (C) 1999 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
 #ifndef _UNIXMBOX_H
 #define _UNIXMBOX_H	1
@@ -40,6 +55,7 @@ typedef struct _unixmbox_data
   {
     unixmbox_message *messages;
     FILE *file;
+    int lockmode;
   }
 unixmbox_data;
 
@@ -49,6 +65,7 @@ int unixmbox_delete (mailbox *mbox, int num);
 int unixmbox_undelete (mailbox *mbox, int num);
 int unixmbox_expunge (mailbox *mbox);
 int unixmbox_is_deleted (mailbox *mbox, int num);
+int unixmbox_lock (mailbox *mbox, int mode);
 int unixmbox_add_message (mailbox *mbox, char *message);
 char *unixmbox_get_body (mailbox *mbox, int num);
 char *unixmbox_get_header (mailbox *mbox, int num);