diff --git a/builtin.cpp b/builtin.cpp
index b084ed5d7..04e3f1343 100644
--- a/builtin.cpp
+++ b/builtin.cpp
@@ -1692,7 +1692,7 @@ static int builtin_function( parser_t &parser, wchar_t **argv )
 				else
 				{
 					errno = 0;
-					pid = wcstol( woptarg, &end, 10 );
+					pid = (pid_t)wcstol( woptarg, &end, 10 );
 					if( errno || !end || *end )
 					{
 						append_format(stderr_buffer,
@@ -1821,7 +1821,7 @@ static int builtin_function( parser_t &parser, wchar_t **argv )
 		for( i=0; i<names.size(); i++ )
 		{
 			const wchar_t *nxt = names.at(i).c_str();
-			int l = wcslen( nxt + 2 );
+			size_t l = wcslen( nxt + 2 );
 			if( chars+l > common_get_width() )
 			{
 				chars = 0;
@@ -2542,7 +2542,7 @@ static int builtin_exit( parser_t &parser, wchar_t **argv )
 {
 	int argc = builtin_count_args( argv );
 
-	int ec=0;
+	long ec=0;
 	switch( argc )
 	{
 		case 1:
@@ -2580,7 +2580,7 @@ static int builtin_exit( parser_t &parser, wchar_t **argv )
 		
 	}
 	reader_exit( 1, 0 );
-	return ec;
+	return (int)ec;
 }
 
 /**
diff --git a/builtin_commandline.cpp b/builtin_commandline.cpp
index b8d3868af..7c9cfd9a9 100644
--- a/builtin_commandline.cpp
+++ b/builtin_commandline.cpp
@@ -127,7 +127,7 @@ static void replace_part( const wchar_t *begin,
 		}
 	}
 	out.append( end );
-	reader_set_buffer( out, (int)out_pos );
+	reader_set_buffer( out, (size_t)out_pos );
 }
 	
 /**
@@ -387,7 +387,7 @@ static int builtin_commandline( parser_t &parser, wchar_t **argv )
 
 			case 'I':
 				current_buffer = woptarg;
-				current_cursor_pos = wcslen( woptarg );
+				current_cursor_pos = (int)wcslen( woptarg );
 				break;
 				
 			case 'C':
@@ -545,8 +545,8 @@ static int builtin_commandline( parser_t &parser, wchar_t **argv )
 			}
 			
 			current_buffer = reader_get_buffer();
-			new_pos = maxi( 0L, mini( (long)new_pos, (long)wcslen( current_buffer ) ) );
-			reader_set_buffer( current_buffer, new_pos );
+			new_pos = maxi( 0L, mini( new_pos, (long)wcslen( current_buffer ) ) );
+			reader_set_buffer( current_buffer, (size_t)new_pos );
 			return 0;
 		}
 		else
diff --git a/complete.cpp b/complete.cpp
index 1050ef432..df95ae58e 100644
--- a/complete.cpp
+++ b/complete.cpp
@@ -339,7 +339,7 @@ class completer_t {
                        
     void complete_cmd_desc( const wcstring &str );
                           
-    bool complete_variable(const wcstring &str, int start_offset);
+    bool complete_variable(const wcstring &str, size_t start_offset);
     
     bool condition_test( const wcstring &condition );
     
@@ -1471,7 +1471,7 @@ bool completer_t::complete_param( const wcstring &scmd_orig, const wcstring &spo
 							int has_arg=0; /* Does this switch have any known arguments  */
 							int req_arg=0; /* Does this switch _require_ an argument */
 
-							int offset = 0;
+							size_t offset = 0;
 							complete_flags_t flags = 0;
 
 															
@@ -1560,11 +1560,11 @@ void completer_t::debug_print_completions()
 /**
    Complete the specified string as an environment variable
 */
-bool completer_t::complete_variable(const wcstring &str, int start_offset)
+bool completer_t::complete_variable(const wcstring &str, size_t start_offset)
 {
     const wchar_t * const whole_var = str.c_str();
 	const wchar_t *var = &whole_var[start_offset];
-	int varlen = wcslen( var );
+	size_t varlen = wcslen( var );
 	int res = 0;
     bool wants_description = (type != COMPLETE_AUTOSUGGEST);
     
@@ -1572,7 +1572,7 @@ bool completer_t::complete_variable(const wcstring &str, int start_offset)
 	for( size_t i=0; i<names.size(); i++ )
 	{
 		const wcstring & env_name = names.at(i);
-		int namelen = env_name.size();
+		size_t namelen = env_name.size();
 		int match=0, match_no_case=0;	
 
 		if( varlen > namelen )
@@ -1667,7 +1667,7 @@ bool completer_t::try_complete_user( const wcstring &str )
 		if( name_end == 0 )
 		{
 			struct passwd *pw;
-			int name_len = wcslen( user_name );
+			size_t name_len = wcslen( user_name );
 			
 			setpwent();
 			
diff --git a/env_universal_common.cpp b/env_universal_common.cpp
index e2c1d62de..66a97fe18 100644
--- a/env_universal_common.cpp
+++ b/env_universal_common.cpp
@@ -431,9 +431,7 @@ static int read_byte( connection_t *src )
 	if( src->buffer_consumed >= src->buffer_used )
 	{
 
-		int res;
-
-		res = read( src->fd, src->buffer, ENV_UNIVERSAL_BUFFER_SIZE );
+		ssize_t res = read( src->fd, src->buffer, ENV_UNIVERSAL_BUFFER_SIZE );
 		
 //		debug(4, L"Read chunk '%.*s'", res, src->buffer );
 		
@@ -692,7 +690,7 @@ static int try_send( message_t *msg,
 	debug( 3,
 		   L"before write of %d chars to fd %d", strlen(msg->body), fd );	
 
-	int res = write( fd, msg->body, strlen(msg->body) );
+	ssize_t res = write( fd, msg->body, strlen(msg->body) );
 
 	if( res != -1 )
 	{
diff --git a/env_universal_common.h b/env_universal_common.h
index 1cfdd156f..14ce77d21 100644
--- a/env_universal_common.h
+++ b/env_universal_common.h
@@ -103,12 +103,12 @@ typedef struct connection
 	/**
 	   Number of bytes that have already been consumed.
 	*/
-	int buffer_consumed;
+	size_t buffer_consumed;
 	
 	/**
 	   Number of bytes that have been read into the buffer. 
 	*/
-	int buffer_used;
+	size_t buffer_used;
 	
 
 	/**
diff --git a/fish_pager.cpp b/fish_pager.cpp
index d108d1161..7c67d3481 100644
--- a/fish_pager.cpp
+++ b/fish_pager.cpp
@@ -480,7 +480,7 @@ static void completion_print( int cols,
 			      int row_stop,
 			      wchar_t *prefix,
 			      int is_quoted,
-			      std::vector<comp_t *> &lst )
+			      const std::vector<comp_t *> &lst )
 {
 
 	size_t rows = (lst.size()-1)/cols+1;
@@ -549,9 +549,9 @@ static int completion_try_print( int cols,
 	*/
 	int print=0;
 	
-	int i, j;
+	long i, j;
 	
-	long rows = (lst.size()-1)/cols+1;
+	int rows = (int)((lst.size()-1)/cols+1);
 	
 	int pref_tot_width=0;
 	int min_tot_width = 0;
@@ -573,7 +573,7 @@ static int completion_try_print( int cols,
 		{
 			int pref,min;
 			comp_t *c;
-			if( (int)lst.size() <= j*rows + i )
+			if( lst.size() <= j*rows + i )
 				continue;
 
 			c = lst.at(j*rows + i );
@@ -613,7 +613,7 @@ static int completion_try_print( int cols,
 	}
 	else
 	{
-		int next_rows = (lst.size()-1)/(cols-1)+1;
+		long next_rows = (lst.size()-1)/(cols-1)+1;
 /*		fwprintf( stderr,
   L"cols %d, min_tot %d, term %d, rows=%d, nextrows %d, termrows %d, diff %d\n",
   cols,
diff --git a/fishd.cpp b/fishd.cpp
index bf4cfcb56..e0a2859d1 100644
--- a/fishd.cpp
+++ b/fishd.cpp
@@ -280,7 +280,7 @@ static int sprint_rand_digits( char *str, int maxlen )
  */
 static char *gen_unique_nfs_filename( const char *filename )
 {
-	int pidlen, hnlen, orglen = strlen( filename );
+	size_t pidlen, hnlen, orglen = strlen( filename );
 	char hostname[HOST_NAME_MAX + 1];
 	char *newname;
 	
@@ -452,7 +452,7 @@ done:
 */
 static char *acquire_socket_lock( const char *sock_name )
 {
-	int len = strlen( sock_name );
+	size_t len = strlen( sock_name );
 	char *lockfile = (char *)malloc( len + strlen( LOCKPOSTFIX ) + 1 );
 	
 	if( lockfile == NULL ) 
diff --git a/parse_util.cpp b/parse_util.cpp
index 181d9c99a..c41a357a8 100644
--- a/parse_util.cpp
+++ b/parse_util.cpp
@@ -135,15 +135,15 @@ int parse_util_get_line_from_offset( const wcstring &str, int pos )
 }
 
 
-int parse_util_get_offset_from_line( const wcstring &str, int line )
+size_t parse_util_get_offset_from_line( const wcstring &str, int line )
 {
     const wchar_t *buff = str.c_str();
-	int i;
+	size_t i;
 	int count = 0;
 	
 	if( line < 0 )
 	{
-		return -1;
+		return (size_t)(-1);
 	}
 
 	if( line == 0 )
@@ -168,19 +168,19 @@ int parse_util_get_offset_from_line( const wcstring &str, int line )
 	}
 }
 
-int parse_util_get_offset( const wcstring &str, int line, int line_offset )
+size_t parse_util_get_offset( const wcstring &str, int line, long line_offset )
 {
     const wchar_t *buff = str.c_str();
-	int off = parse_util_get_offset_from_line( buff, line );
-	int off2 = parse_util_get_offset_from_line( buff, line+1 );
-	int line_offset2 = line_offset;
+	size_t off = parse_util_get_offset_from_line( buff, line );
+	size_t off2 = parse_util_get_offset_from_line( buff, line+1 );
+	long line_offset2 = line_offset;
 	
-	if( off < 0 )
+	if( off == (size_t)(-1) )
 	{
 		return -1;
 	}
 	
-	if( off2 < 0 )
+	if( off2 == (size_t)(-1) )
 	{
 		off2 = (int)(wcslen( buff )+1);
 	}
@@ -292,7 +292,7 @@ int parse_util_locate_cmdsubst( const wchar_t *in,
 
 
 void parse_util_cmdsubst_extent( const wchar_t *buff,
-								 int cursor_pos,
+								 size_t cursor_pos,
 								 const wchar_t **a, 
 								 const wchar_t **b )
 {
@@ -477,7 +477,7 @@ void parse_util_job_extent( const wchar_t *buff,
 
 
 void parse_util_token_extent( const wchar_t *buff,
-							  int cursor_pos,
+							  size_t cursor_pos,
 							  const wchar_t **tok_begin,
 							  const wchar_t **tok_end,
 							  const wchar_t **prev_begin, 
diff --git a/parse_util.h b/parse_util.h
index a3ffc193d..e533fb897 100644
--- a/parse_util.h
+++ b/parse_util.h
@@ -40,7 +40,7 @@ int parse_util_locate_cmdsubst( const wchar_t *in,
    \param b the end of the searched string
 */
 void parse_util_cmdsubst_extent( const wchar_t *buff,
-								 int cursor_pos,
+								 size_t cursor_pos,
 								 const wchar_t **a, 
 								 const wchar_t **b );
 
@@ -84,7 +84,7 @@ void parse_util_job_extent( const wchar_t *buff,
    \param prev_end the end of the token before the current token
 */
 void parse_util_token_extent( const wchar_t *buff,
-							  int cursor_pos,
+							  size_t cursor_pos,
 							  const wchar_t **tok_begin,
 							  const wchar_t **tok_end,
 							  const wchar_t **prev_begin, 
@@ -104,13 +104,13 @@ int parse_util_get_line_from_offset( const wcstring &str, int pos );
 /**
    Get the offset of the first character on the specified line
  */
-int parse_util_get_offset_from_line( const wcstring &str, int line );
+size_t parse_util_get_offset_from_line( const wcstring &str, int line );
 
 
 /**
    Return the total offset of the buffer for the cursor position nearest to the specified poition
  */
-int parse_util_get_offset( const wcstring &str, int line, int line_offset );
+size_t parse_util_get_offset( const wcstring &str, int line, long line_offset );
 
 /**
    Set the argv environment variable to the specified null-terminated
diff --git a/reader.cpp b/reader.cpp
index 3bae07b59..9bfa1b065 100644
--- a/reader.cpp
+++ b/reader.cpp
@@ -1641,7 +1641,7 @@ void reader_sanity_check()
    Set the specified string from the history as the current buffer. Do
    not modify prefix_width.
 */
-static void set_command_line_and_position( const wcstring &new_str, int pos )
+static void set_command_line_and_position( const wcstring &new_str, size_t pos )
 {
     data->command_line = new_str;
     data->command_line_changed();
@@ -1654,7 +1654,7 @@ void reader_replace_current_token( const wchar_t *new_token )
 {
 
 	const wchar_t *begin, *end;
-	int new_pos;
+	size_t new_pos;
 
 	/* Find current token */
     const wchar_t *buff = data->command_line.c_str();
@@ -1985,7 +1985,7 @@ history_t *reader_get_history(void) {
 	return data ? data->history : NULL;
 }
 
-void reader_set_buffer( const wcstring &b, int p )
+void reader_set_buffer( const wcstring &b, size_t p )
 {
 	if( !data )
 		return;
@@ -3232,14 +3232,12 @@ static int read_ni( int fd, io_data_t *io )
 	if( in_stream != 0 )
 	{
 		wchar_t *str;
-		int acc_used;
+		size_t acc_used;
 
 		while(!feof( in_stream ))
 		{
 			char buff[4096];
-			int c;
-
-			c = fread(buff, 1, 4096, in_stream);
+			size_t c = fread(buff, 1, 4096, in_stream);
 			
 			if( ferror( in_stream ) && ( errno != EINTR ) )
 			{
diff --git a/reader.h b/reader.h
index f2156b07c..846e0a0ab 100644
--- a/reader.h
+++ b/reader.h
@@ -100,9 +100,10 @@ history_t *reader_get_history(void);
    Set the string of characters in the command buffer, as well as the cursor position.
 
    \param b the new buffer value
-   \param p the cursor position. If \c p is less than zero, the cursor is placed on the last character.
+   \param p the cursor position. If \c p is larger than the length of the command line,
+            the cursor is placed on the last character.
 */
-void reader_set_buffer( const wcstring &b, int p );
+void reader_set_buffer( const wcstring &b, size_t p );
 
 /**
    Get the current cursor position in the command line. If interactive
diff --git a/screen.cpp b/screen.cpp
index 7087f14e4..8ec4278c2 100644
--- a/screen.cpp
+++ b/screen.cpp
@@ -113,7 +113,7 @@ static int try_sequence( const char *seq, const wchar_t *str )
    Returns the number of columns left until the next tab stop, given
    the current cursor postion.
  */
-static int next_tab_stop( int in )
+static size_t next_tab_stop( size_t in )
 {
 	/*
 	  Assume tab stops every 8 characters if undefined
@@ -151,9 +151,9 @@ static int is_term256_escape(const wchar_t *str) {
    to detect common escape sequences that may be embeded in a prompt,
    such as color codes.
 */
-static int calc_prompt_width( const wchar_t *prompt )
+static size_t calc_prompt_width( const wchar_t *prompt )
 {
-	int res = 0;
+	size_t res = 0;
 	size_t j, k;
 
 	for( j=0; prompt[j]; j++ )
@@ -416,7 +416,7 @@ static void s_desired_append_char( screen_t *s,
 				   wchar_t b,
 				   int c, 
 				   int indent,
-				   int prompt_width )
+				   size_t prompt_width )
 {
 	int line_no = s->desired.cursor[1];
 	
@@ -653,7 +653,7 @@ static size_t line_shared_prefix(const line_t &a, const line_t &b)
 */
 static void s_update( screen_t *scr, const wchar_t *prompt )
 {
-	int prompt_width = calc_prompt_width( prompt );
+	size_t prompt_width = calc_prompt_width( prompt );
 	int screen_width = common_get_width();
 	int need_clear = scr->need_clear;
 	data_buffer_t output;
@@ -673,25 +673,25 @@ static void s_update( screen_t *scr, const wchar_t *prompt )
 		s_move( scr, &output, 0, 0 );
 		s_write_str( &output, prompt );
         scr->actual_prompt = prompt;
-		scr->actual.cursor[0] = prompt_width;
+		scr->actual.cursor[0] = (int)prompt_width;
 	}
 	
     for (size_t i=0; i < scr->desired.line_count(); i++)
 	{
 		const line_t &o_line = scr->desired.line(i);
 		line_t &s_line = scr->actual.create_line(i);
-		int start_pos = (i==0 ? prompt_width : 0);
+		size_t start_pos = (i==0 ? prompt_width : 0);
         int current_width = 0;
         
 		if( need_clear )
 		{
-			s_move( scr, &output, start_pos, (int)i );
+			s_move( scr, &output, (int)start_pos, (int)i );
 			s_write_mbs( &output, clr_eol);
             s_line.clear();
 		}
         
         /* Note that skip_remaining is a width, not a character count */
-        int skip_remaining = start_pos;
+        size_t skip_remaining = start_pos;
         
         /* Compute how much we should skip. At a minimum we skip over the prompt. But also skip over the shared prefix of what we want to output now, and what we output before, to avoid repeatedly outputting it. */
         size_t shared_prefix = line_shared_prefix(o_line, s_line);
@@ -771,18 +771,18 @@ static int is_dumb()
 void s_write( screen_t *s,
 	      const wchar_t *prompt,
 	      const wchar_t *commandline, 
-	      int explicit_len,
+	      size_t explicit_len,
 	      const int *c, 
 	      const int *indent,
 	      int cursor )
 {
-	int i;
 	int cursor_arr[2];
 
-	int prompt_width;
-	int screen_width;
+	size_t prompt_width;
+	size_t screen_width;
 
-	int max_line_width = 0, current_line_width = 0, newline_count = 0, explicit_portion_width = 0;
+	int current_line_width = 0, newline_count = 0, explicit_portion_width = 0;
+    size_t max_line_width = 0;
 	
 	CHECK( s, );
 	CHECK( prompt, );
@@ -838,8 +838,8 @@ void s_write( screen_t *s,
 	/*
 	  Check if we are overflowing
 	 */
-    int last_char_that_fits = 0;
-	for( i=0; commandline[i]; i++ )
+    size_t last_char_that_fits = 0;
+	for( size_t i=0; commandline[i]; i++ )
 	{
 		if( commandline[i] == L'\n' )
 		{
@@ -874,7 +874,7 @@ void s_write( screen_t *s,
         truncated_autosuggestion_line.push_back(ellipsis_char);
         commandline = truncated_autosuggestion_line.c_str();
     }
-	for( i=0; i<prompt_width; i++ )
+	for( size_t i=0; i<prompt_width; i++ )
 	{
 		s_desired_append_char( s, L' ', 0, 0, prompt_width );
 	}
@@ -889,6 +889,7 @@ void s_write( screen_t *s,
 		prompt_width=0;
 	}
 	
+    int i;
 	for( i=0; commandline[i]; i++ )
 	{
 		int col = c[i];
@@ -917,7 +918,6 @@ void s_write( screen_t *s,
 			cursor_arr[0] = s->desired.cursor[0] - fish_wcwidth(commandline[i]);
 			cursor_arr[1] = s->desired.cursor[1];
 		}
-		
 	}
 	if( i == cursor )
 	{
diff --git a/screen.h b/screen.h
index edaba1335..ba72d4af7 100644
--- a/screen.h
+++ b/screen.h
@@ -147,7 +147,7 @@ class screen_t
 void s_write( screen_t *s, 
 			  const wchar_t *prompt, 
 			  const wchar_t *commandline,
-			  int explicit_len,
+			  size_t explicit_len,
 			  const int *colors, 
 			  const int *indent,
 			  int cursor_pos );
diff --git a/set_color.cpp b/set_color.cpp
index 33f755c93..667c496cb 100644
--- a/set_color.cpp
+++ b/set_color.cpp
@@ -58,6 +58,10 @@
 */
 #define GETOPT_STRING "b:hvocu"
 
+#ifdef _
+ #undef _
+#endif
+
 #ifdef USE_GETTEXT
 #define _(string) gettext(string)
 #else
diff --git a/tokenizer.cpp b/tokenizer.cpp
index ae70f3162..1e4704b40 100644
--- a/tokenizer.cpp
+++ b/tokenizer.cpp
@@ -141,7 +141,7 @@ void tok_init( tokenizer *tok, const wchar_t *b, int flags )
 	tok->accept_unfinished = !! (flags & TOK_ACCEPT_UNFINISHED);
 	tok->show_comments = !! (flags & TOK_SHOW_COMMENTS);
     tok->squash_errors = !! (flags & TOK_SQUASH_ERRORS);
-	tok->has_next=1;
+	tok->has_next=true;
 
 	tok->has_next = (*b != L'\0');
 	tok->orig_buff = tok->buff = b;
@@ -153,8 +153,6 @@ void tok_destroy( tokenizer *tok )
 	CHECK( tok, );
 	
 	free( tok->last );
-	if( tok->free_orig )
-		free( (void *)tok->orig_buff );
 }
 
 int tok_last_type( tokenizer *tok )
@@ -432,13 +430,12 @@ static void read_string( tokenizer *tok )
 static void read_comment( tokenizer *tok )
 {
 	const wchar_t *start;
-	int len;
 
 	start = tok->buff;
 	while( *(tok->buff)!= L'\n' && *(tok->buff)!= L'\0' )
 		tok->buff++;
 
-	len = tok->buff - start;
+	size_t len = tok->buff - start;
 	if( !check_size( tok, len ))
 		return;
 
@@ -553,7 +550,7 @@ void tok_next( tokenizer *tok )
 	
 	if( tok_last_type( tok ) == TOK_ERROR )
 	{
-		tok->has_next=0;
+		tok->has_next=false;
 		return;
 	}
 
@@ -610,7 +607,7 @@ void tok_next( tokenizer *tok )
 		case L'\0':
 			tok->last_type = TOK_END;
 			/*fwprintf( stderr, L"End of string\n" );*/
-			tok->has_next = 0;
+			tok->has_next = false;
 			break;
 		case 13:
 		case L'\n':
@@ -700,7 +697,7 @@ int tok_get_pos( tokenizer *tok )
 {
 	CHECK( tok, 0 );
 	
-	return tok->last_pos;
+	return (int)tok->last_pos;
 }
 
 
@@ -709,7 +706,7 @@ void tok_set_pos( tokenizer *tok, int pos )
 	CHECK( tok, );
 	
 	tok->buff = tok->orig_buff + pos;
-	tok->has_next = 1;
+	tok->has_next = true;
 	tok_next( tok );
 }
 
diff --git a/tokenizer.h b/tokenizer.h
index ff7c38e90..7287ccd0f 100644
--- a/tokenizer.h
+++ b/tokenizer.h
@@ -79,15 +79,13 @@ struct tokenizer
 	/** Length of last token*/
 	size_t last_len;
 	/** Offset of last token*/
-	int last_pos;
+	size_t last_pos;
 	/** Whether there are more tokens*/
-	int has_next;
+	bool has_next;
 	/** Whether incomplete tokens are accepted*/
-	int accept_unfinished;
+	bool accept_unfinished;
 	/** Whether commants should be returned*/
-	int show_comments;
-	/** Flag set to true of the orig_buff points to an internal string that needs to be free()d when deallocating the tokenizer. */
-	int free_orig;
+	bool show_comments;
 	/** Type of last quote, can be either ' or ".*/
 	wchar_t last_quote;
 	/** Last error */
diff --git a/wgetopt.cpp b/wgetopt.cpp
index 517862885..b956b5a52 100644
--- a/wgetopt.cpp
+++ b/wgetopt.cpp
@@ -179,6 +179,10 @@ static char *posixly_correct;
 /**
    Use translation functions if available
 */
+#ifdef _
+ #undef _
+#endif
+
 #ifdef HAVE_TRANSLATE_H
 #ifdef USE_GETTEXT
 #define _(string) wgettext(string)