RFA: >, >>, and "tee" operators

[Daniel Jacobowitz <drow at mvista dot com>]

Here we go.  They only work quite right for the CLI; they sort-of work for
other front-ends, and print a warning to that effect.  Documentation
included.  These are pretty much how Tom originally did them:

> file
>> file

and my additions:
tee file
tee -a file

Any of the commands without a filename will end redirection.

Comments?  OK to apply?  Design too ugly?

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer

2002-07-23  Tom Tromey  <tromey@redhat.com>
            Daniel Jacobowitz  <drow@mvista.com>

	* cli-out.c (struct ui_out_data): Add original_stream.
	(cli_redirect): New function.
	(cli_ui_out_impl): Add cli_redirect.
	(cli_out_new): Initialize original_stream.
	* ui-file.c (struct tee_file, tee_file_new, tee_file_delete)
	(tee_file_flush, tee_file_write, tee_file_fputs)
	(tee_file_isatty): New.
	* ui-file.h (tee_file_new): Add prototype.
	* ui-out.c (default_ui_out_impl): Add NULL for redirect member.
	(uo_redirect, ui_out_redirect): New.
	* ui-out.h (struct ui_out_impl): Add redirect member.
	(redirect_ftype): New.
        * cli/cli-decode.c (lookup_cmd): Allow `>' in command name.
        (lookup_cmd_1): Likewise.
        * top.c (redirect_output): New function.
        (append_output): Likewise.
        (handle_redirections): Likewise.
        (pop_output_files): Likewise.
        (init_main): Create ">", ">>", and "tee" commands.

2002-07-23  Daniel Jacobowitz  <drow@mvista.com>

	* mi-out.c (mi_ui_out_impl): Add NULL for redirect member.

2002-07-23  Daniel Jacobowitz  <drow@mvista.com>

	* tui-out.c (tui_ui_out_impl): Add NULL for redirect member.

2002-07-23  Daniel Jacobowitz  <drow@mvista.com>

	* gdb.texinfo (Redirecting output): New chapter.

Index: cli-out.c
===================================================================
RCS file: /cvs/src/src/gdb/cli-out.c,v
retrieving revision 1.14
diff -u -p -r1.14 cli-out.c
--- cli-out.c	19 Mar 2002 02:51:04 -0000	1.14
+++ cli-out.c	23 Jul 2002 18:26:19 -0000
@@ -31,6 +31,7 @@
 struct ui_out_data
   {
     struct ui_file *stream;
+    struct ui_file *original_stream;
     int suppress_output;
   };
 
@@ -63,6 +64,7 @@ static void cli_message (struct ui_out *
 			 const char *format, va_list args);
 static void cli_wrap_hint (struct ui_out *uiout, char *identstring);
 static void cli_flush (struct ui_out *uiout);
+static int cli_redirect (struct ui_out *uiout, struct ui_file *outstream);
 
 /* This is the CLI ui-out implementation functions vector */
 
@@ -86,6 +88,7 @@ static struct ui_out_impl cli_ui_out_imp
   cli_message,
   cli_wrap_hint,
   cli_flush,
+  cli_redirect,
   0, /* Does not need MI hacks (i.e. needs CLI hacks).  */
 };
 
@@ -323,6 +326,24 @@ cli_flush (struct ui_out *uiout)
   gdb_flush (data->stream);
 }
 
+int
+cli_redirect (struct ui_out *uiout, struct ui_file *outstream)
+{
+  struct ui_out_data *data = ui_out_data (uiout);
+  if (outstream != NULL)
+    {
+      data->original_stream = data->stream;
+      data->stream = outstream;
+    }
+  else if (data->original_stream != NULL)
+    {
+      data->stream = data->original_stream;
+      data->original_stream = NULL;
+    }
+
+  return 0;
+}
+
 /* local functions */
 
 /* Like cli_field_fmt, but takes a variable number of args
@@ -361,6 +382,7 @@ cli_out_new (struct ui_file *stream)
 
   struct ui_out_data *data = XMALLOC (struct ui_out_data);
   data->stream = stream;
+  data->original_stream = NULL;
   data->suppress_output = 0;
   return ui_out_new (&cli_ui_out_impl, data, flags);
 }
Index: top.c
===================================================================
RCS file: /cvs/src/src/gdb/top.c,v
retrieving revision 1.64
diff -u -p -r1.64 top.c
--- top.c	11 Jul 2002 13:50:49 -0000	1.64
+++ top.c	23 Jul 2002 18:26:19 -0000
@@ -1707,6 +1707,133 @@ dont_repeat_command (char *ignored, int 
 				   necessarily reading from stdin.  */
 }
 
+/* Functions and variables for gdb output redirection.  */
+
+/* These hold the pushed copies of the gdb output files.
+   If NULL then nothing has yet been pushed.  */
+static struct ui_file *saved_stdout;
+static struct ui_file *saved_stderr;
+static struct ui_file *saved_stdlog;
+static struct ui_file *saved_stdtarg;
+static char *saved_filename;
+
+/* If we've pushed output files, close them and pop them.  */
+static void
+pop_output_files ()
+{
+  if (saved_stdout != NULL)
+    {
+      xfree (saved_filename);
+      saved_filename = NULL;
+
+      /* Only delete one of the files -- they are all set to the same
+	 value.  */
+      ui_file_delete (gdb_stdout);
+      gdb_stdout = saved_stdout;
+      gdb_stderr = saved_stderr;
+      gdb_stdlog = saved_stdlog;
+      gdb_stdtarg = saved_stdtarg;
+      saved_stdout = NULL;
+      saved_stderr = NULL;
+      saved_stdlog = NULL;
+      saved_stdtarg = NULL;
+
+      ui_out_redirect (uiout, NULL);
+    }
+}
+
+/* This is a helper for the `>', `>>', and `tee' redirection commands.  */
+static void
+handle_redirections (char *command, char *filename, char *mode, int tee)
+{
+  struct ui_file *output;
+
+  if (saved_filename != NULL)
+    fprintf_unfiltered (saved_stdout, "Done redirecting to %s.\n", saved_filename);
+
+  pop_output_files ();
+
+  /* Skip whitespace.  */
+  if (filename == NULL)
+    return;
+
+  while (*filename && isspace (*filename))
+    ++filename;
+  
+  if (*filename == 0)
+    return;
+
+  /* It would be nice if the syntax was:
+     > FILE [COMMAND]
+     .. if COMMAND is specified then it (and only it) is run with
+     redirections.  This means inventing a quoting syntax for the file
+     name though.  */
+  output = gdb_fopen (filename, mode);
+  if (output == NULL)
+    perror_with_name (command);
+
+  /* Redirects everything to gdb_stdout while this is running.  */
+  if (tee)
+    {
+      output = tee_file_new (gdb_stdout, 0, output, 1);
+      if (output == NULL)
+	perror_with_name (command);
+      fprintf_unfiltered (gdb_stdout, "Copying output to %s.\n", filename);
+    }
+  else
+    fprintf_unfiltered (gdb_stdout, "Redirecting output to %s.\n", filename);
+
+  saved_filename = xstrdup (filename);
+  saved_stdout = gdb_stdout;
+  saved_stderr = gdb_stderr;
+  saved_stdlog = gdb_stdlog;
+  saved_stdtarg = gdb_stdtarg;
+  gdb_stdout = output;
+  gdb_stderr = output;
+  gdb_stdlog = output;
+  gdb_stdtarg = output;
+  if (ui_out_redirect (uiout, gdb_stdout) < 0)
+    warning ("Current output protocol does not support redirection");
+}
+
+/* Redirect output by overwriting a file.  */
+/* ARGSUSED */
+static void
+redirect_output (char *args, int from_tty)
+{
+  handle_redirections (">", args, "w", 0);
+}
+
+/* Redirect output by appending to a file.  */
+/* ARGSUSED */
+static void
+append_output (char *args, int from_tty)
+{
+  handle_redirections (">>", args, "a", 0);
+}
+
+/* Redirect output by writing to a file and writing to the screen.  */
+/* ARGSUSED */
+static void
+tee_output (char *args, int from_tty)
+{
+  if (args)
+    {
+      /* Check for "-a".  */
+      while (*args && isspace (*args))
+	++args;
+
+      if (args[0] == '-' && args[1] == 'a' && isspace (args[2]))
+	{
+	  handle_redirections ("tee", args + 3, "a", 1);
+	  return;
+	}
+    }
+
+  handle_redirections ("tee", args, "w", 1);
+}
+
+
 /* Functions to manipulate command line editing control variables.  */
 
 /* Number of commands to print in each call to show_commands.  */
@@ -2040,6 +2167,17 @@ ie. the number of previous commands to k
 Use \"on\" to enable the notification, and \"off\" to disable it.", &setlist),
 	 &showlist);
     }
+
+  add_com (">", no_class, redirect_output,
+	   "Redirect further gdb output to a file.\n\
+If no filename is given, any previous redirection is stopped.");
+  add_com (">>", no_class, append_output,
+	   "Append further gdb output to a file.\n\
+If no filename is given, any previous redirection is stopped.");
+  add_com ("tee", no_class, tee_output,
+	   "Send further gdb output to both the terminal and a file.\n\
+If \"-a\" is specified append to the file; otherwise overwrite it.\n\
+If no filename is given, any previous redirection is stopped.");
 }
 
 void
Index: ui-file.c
===================================================================
RCS file: /cvs/src/src/gdb/ui-file.c,v
retrieving revision 1.8
diff -u -p -r1.8 ui-file.c
--- ui-file.c	19 Mar 2002 02:51:07 -0000	1.8
+++ ui-file.c	23 Jul 2002 18:26:19 -0000
@@ -483,3 +483,97 @@ gdb_fopen (char *name, char *mode)
     return NULL;
   return stdio_file_new (f, 1);
 }
+
+/* ``struct ui_file'' implementation that maps onto two ui-file objects.  */
+
+static ui_file_write_ftype tee_file_write;
+static ui_file_fputs_ftype tee_file_fputs;
+static ui_file_isatty_ftype tee_file_isatty;
+static ui_file_delete_ftype tee_file_delete;
+static ui_file_flush_ftype tee_file_flush;
+
+static int tee_file_magic;
+
+struct tee_file
+  {
+    int *magic;
+    struct ui_file *one, *two;
+    int close_one, close_two;
+  };
+
+struct ui_file *
+tee_file_new (struct ui_file *one, int close_one,
+	      struct ui_file *two, int close_two)
+{
+  struct ui_file *ui_file = ui_file_new ();
+  struct tee_file *tee = xmalloc (sizeof (struct tee_file));
+  tee->magic = &tee_file_magic;
+  tee->one = one;
+  tee->two = two;
+  tee->close_one = close_one;
+  tee->close_two = close_two;
+  set_ui_file_data (ui_file, tee, tee_file_delete);
+  set_ui_file_flush (ui_file, tee_file_flush);
+  set_ui_file_write (ui_file, tee_file_write);
+  set_ui_file_fputs (ui_file, tee_file_fputs);
+  set_ui_file_isatty (ui_file, tee_file_isatty);
+  return ui_file;
+}
+
+static void
+tee_file_delete (struct ui_file *file)
+{
+  struct tee_file *tee = ui_file_data (file);
+  if (tee->magic != &tee_file_magic)
+    internal_error (__FILE__, __LINE__,
+		    "tee_file_delete: bad magic number");
+  if (tee->close_one)
+    ui_file_delete (tee->one);
+  if (tee->close_two)
+    ui_file_delete (tee->two);
+
+  xfree (tee);
+}
+
+static void
+tee_file_flush (struct ui_file *file)
+{
+  struct tee_file *tee = ui_file_data (file);
+  if (tee->magic != &tee_file_magic)
+    internal_error (__FILE__, __LINE__,
+		    "tee_file_flush: bad magic number");
+  tee->one->to_flush (tee->one);
+  tee->two->to_flush (tee->two);
+}
+
+static void
+tee_file_write (struct ui_file *file, const char *buf, long length_buf)
+{
+  struct tee_file *tee = ui_file_data (file);
+  if (tee->magic != &tee_file_magic)
+    internal_error (__FILE__, __LINE__,
+		    "tee_file_write: bad magic number");
+  ui_file_write (tee->one, buf, length_buf);
+  ui_file_write (tee->two, buf, length_buf);
+}
+
+static void
+tee_file_fputs (const char *linebuffer, struct ui_file *file)
+{
+  struct tee_file *tee = ui_file_data (file);
+  if (tee->magic != &tee_file_magic)
+    internal_error (__FILE__, __LINE__,
+		    "tee_file_fputs: bad magic number");
+  tee->one->to_fputs (linebuffer, tee->one);
+  tee->two->to_fputs (linebuffer, tee->two);
+}
+
+static int
+tee_file_isatty (struct ui_file *file)
+{
+  struct tee_file *tee = ui_file_data (file);
+  if (tee->magic != &tee_file_magic)
+    internal_error (__FILE__, __LINE__,
+		    "tee_file_isatty: bad magic number");
+  return (0);
+}
Index: ui-file.h
===================================================================
RCS file: /cvs/src/src/gdb/ui-file.h,v
retrieving revision 1.2
diff -u -p -r1.2 ui-file.h
--- ui-file.h	6 Mar 2001 08:21:17 -0000	1.2
+++ ui-file.h	23 Jul 2002 18:26:19 -0000
@@ -90,4 +90,11 @@ extern struct ui_file *stdio_fileopen (F
 /* Open NAME returning an STDIO based UI_FILE. */
 extern struct ui_file *gdb_fopen (char *name, char *mode);
 
+/* Create a file which writes to both ONE and TWO.  CLOSE_ONE
+   and CLOSE_TWO indicate whether the original files should be
+   closed when the new file is closed.  */
+struct ui_file *tee_file_new (struct ui_file *one,
+			      int close_one,
+			      struct ui_file *two,
+			      int close_two);
 #endif
Index: ui-out.c
===================================================================
RCS file: /cvs/src/src/gdb/ui-out.c,v
retrieving revision 1.22
diff -u -p -r1.22 ui-out.c
--- ui-out.c	5 May 2002 03:17:21 -0000	1.22
+++ ui-out.c	23 Jul 2002 18:26:20 -0000
@@ -206,6 +206,7 @@ struct ui_out_impl default_ui_out_impl =
   default_message,
   default_wrap_hint,
   default_flush,
+  NULL,
   0, /* Does not need MI hacks.  */
 };
 
@@ -254,6 +255,7 @@ static void uo_message (struct ui_out *u
 			const char *format, va_list args);
 static void uo_wrap_hint (struct ui_out *uiout, char *identstring);
 static void uo_flush (struct ui_out *uiout);
+static int uo_redirect (struct ui_out *uiout, struct ui_file *outstream);
 
 /* Prototypes for local functions */
 
@@ -639,6 +641,12 @@ ui_out_flush (struct ui_out *uiout)
   uo_flush (uiout);
 }
 
+int
+ui_out_redirect (struct ui_out *uiout, struct ui_out *outstream)
+{
+  uo_redirect (uiout, outstream);
+}
+
 /* set the flags specified by the mask given */
 int
 ui_out_set_flags (struct ui_out *uiout, int mask)
@@ -980,6 +988,14 @@ uo_flush (struct ui_out *uiout)
   if (!uiout->impl->flush)
     return;
   uiout->impl->flush (uiout);
+}
+
+int
+uo_redirect (struct ui_out *uiout, struct ui_file *outstream)
+{
+  if (!uiout->impl->redirect)
+    return -1;
+  uiout->impl->redirect (uiout, outstream);
 }
 
 /* local functions */
Index: ui-out.h
===================================================================
RCS file: /cvs/src/src/gdb/ui-out.h,v
retrieving revision 1.15
diff -u -p -r1.15 ui-out.h
--- ui-out.h	6 Jul 2001 03:53:11 -0000	1.15
+++ ui-out.h	23 Jul 2002 18:26:20 -0000
@@ -237,6 +237,8 @@ typedef void (message_ftype) (struct ui_
 			      const char *format, va_list args);
 typedef void (wrap_hint_ftype) (struct ui_out * uiout, char *identstring);
 typedef void (flush_ftype) (struct ui_out * uiout);
+typedef int (redirect_ftype) (struct ui_out * uiout,
+			      struct ui_file * outstream);
 
 /* ui-out-impl */
 
@@ -260,6 +262,7 @@ struct ui_out_impl
     message_ftype *message;
     wrap_hint_ftype *wrap_hint;
     flush_ftype *flush;
+    redirect_ftype *redirect;
     int is_mi_like_p;
   };
 
Index: cli/cli-decode.c
===================================================================
RCS file: /cvs/src/src/gdb/cli/cli-decode.c,v
retrieving revision 1.27
diff -u -p -r1.27 cli-decode.c
--- cli/cli-decode.c	3 Jul 2002 17:35:21 -0000	1.27
+++ cli/cli-decode.c	23 Jul 2002 18:26:20 -0000
@@ -923,7 +923,7 @@ lookup_cmd_1 (char **text, struct cmd_li
      so that "set args_foo()" doesn't get interpreted as
      "set args _foo()".  */
   for (p = *text;
-       *p && (isalnum (*p) || *p == '-' || *p == '_' ||
+       *p && (isalnum (*p) || *p == '-' || *p == '_' || *p == '>' || 
 	      (tui_version &&
 	       (*p == '+' || *p == '<' || *p == '>' || *p == '$')) ||
 	      (xdb_commands && (*p == '!' || *p == '/' || *p == '?')));
@@ -1086,7 +1086,7 @@ lookup_cmd (char **line, struct cmd_list
 	    {
 	      char *p = *line, *q;
 
-	      while (isalnum (*p) || *p == '-')
+	      while (isalnum (*p) || *p == '-' || *p == '>')
 		p++;
 
 	      q = (char *) alloca (p - *line + 1);
Index: doc/gdb.texinfo
===================================================================
RCS file: /cvs/src/src/gdb/doc/gdb.texinfo,v
retrieving revision 1.104
diff -u -p -r1.104 gdb.texinfo
--- doc/gdb.texinfo	9 Jul 2002 15:59:18 -0000	1.104
+++ doc/gdb.texinfo	23 Jul 2002 18:26:24 -0000
@@ -752,6 +752,7 @@ type @kbd{quit} or @kbd{C-d} to exit.
 * Invoking GDB::                How to start @value{GDBN}
 * Quitting GDB::                How to quit @value{GDBN}
 * Shell Commands::              How to use shell commands inside @value{GDBN}
+* Redirecting output::          How to redirect @value{GDBN}'s output to files
 @end menu
 
 @node Invoking GDB
@@ -1201,6 +1202,31 @@ You do not have to use the @code{shell} 
 Execute the @code{make} program with the specified
 arguments.  This is equivalent to @samp{shell make @var{make-args}}.
 @end table
+
+@node Redirecting output
+@section Redirecting output
+
+You may want to save the output of @value{GDBN} commands to a file.
+There are three commands to control @value{GDBN}'s logging.
+
+@table @code
+@kindex >
+@cindex redirect
+@item > @var{file}
+Redirect all output to @var{file}, overwriting it.
+@kindex >>
+@cindex append
+@item >> @var{file}
+Redirect all output to @var{file}, appending to it.
+@kindex tee
+@cindex tee
+@item tee [-a] @var{file}
+Copy output to both the screen and @var{file}, overwriting it unless -a
+(append) is specified.
+@end table
+
+To end the redirection and return to normal output, just use any of the
+redirection commands without specifying a filename.
 
 @node Commands
 @chapter @value{GDBN} Commands
Index: mi/mi-out.c
===================================================================
RCS file: /cvs/src/src/gdb/mi/mi-out.c,v
retrieving revision 1.23
diff -u -p -r1.23 mi-out.c
--- mi/mi-out.c	19 Mar 2002 02:51:08 -0000	1.23
+++ mi/mi-out.c	23 Jul 2002 18:26:25 -0000
@@ -85,6 +85,7 @@ struct ui_out_impl mi_ui_out_impl =
   mi_message,
   mi_wrap_hint,
   mi_flush,
+  NULL,
   1, /* Needs MI hacks.  */
 };
 
Index: tui/tui-out.c
===================================================================
RCS file: /cvs/src/src/gdb/tui/tui-out.c,v
retrieving revision 1.2
diff -u -p -r1.2 tui-out.c
--- tui/tui-out.c	19 Mar 2002 02:51:09 -0000	1.2
+++ tui/tui-out.c	23 Jul 2002 18:26:25 -0000
@@ -88,6 +88,7 @@ static struct ui_out_impl tui_ui_out_imp
   tui_message,
   tui_wrap_hint,
   tui_flush,
+  NULL,
   0, /* Does not need MI hacks (i.e. needs CLI hacks).  */
 };