gdbmtool: new command "perror"; new options -t, -T; improve timing output

* doc/gdbm.texi: Document the perror command.
* src/gdbmshell.c: New command: perror.
(run_command): In timing mode, print also user and system CPU times.
Print traces on stderr.
* src/gdbmtool.c: New options: -t (--trace) and -T (--timing).

3 files changed, 162 insertions, 14 deletions

diff --git a/doc/gdbm.texi b/doc/gdbm.texi
index ee24b48..9a5b676 100644
--- a/doc/gdbm.texi
+++ b/doc/gdbm.texi
@@ -3015,6 +3015,16 @@ Disable file locking.
 @itemx --no-mmap
 Disable memory mapping.
 
+@item -T
+@itemx --timing
+Print time spent in each command.  This is equivalent to setting the
+@code{timing} variable.  @xref{variables, timing}.
+
+@item -t
+@itemx --trace
+Enable command tracing.  This is equivalent to setting the
+@code{trace} variable.  @xref{variables, trace}.
+
 @anchor{-q option}
 @item -q
 @itemx --quiet
@@ -3192,6 +3202,28 @@ lines of a multi-line command.
 The default value is @samp{%_>%_}.
 @end deftypevr
 
+@deftypevr {gdbmtool variable} bool timing
+When each command terminates, print an additional line listing times
+spent in that command.  The line is formatted as follows:
+
+@example
+[reorganize r=0.070481 u=0.000200 s=0.000033]
+@end example
+
+@noindent
+Here, @samp{reorganize} is the name of the command that finished, the
+number after @samp{r=} is real time spent executing the command, the
+number after @samp{u=} is the user CPU time used and the number after
+@samp{s=} is the system CPU time used.
+@end deftypevr
+
+@deftypevr {gdbmtool variable} bool trace
+Enable command tracing.  This is similar to the shell @option{-t}
+option: before executing each command, @command{gdbmtool} will print
+on standard error a line starting with a plus sign and followed by the
+command name and its arguments.
+@end deftypevr
+
 @anchor{quiet}
 @deftypevr {gdbmtool variable} bool quiet
 Whether to display a welcome banner at startup.  To affect
@@ -3565,6 +3597,26 @@ Synchronize after each write.  Default is @code{off}.
 @xref{open parameters}, for a detailed description of these variables.
 @end deffn
 
+@deffn {command verb} perror [@var{code}]
+Describe the given GDBM error code.
+
+The descripion occupies one or two lines.  The second line is present
+if the system error number should be checked when handling this code.
+In this case, the second line states @samp{Examine errno}.
+
+If @var{code} is omitted, the latest error that occurred in the
+current database is described.  Second line of the output (if
+present), contains description of the latest system error.
+
+Example:
+
+@example
+gdbmtool> perror 3
+GDBM error code 3: "File open error"
+Examine errno.
+@end example
+@end deffn
+
 @deffn {command verb} quit
 Close the database and quit the utility.
 @end deffn
diff --git a/src/gdbmshell.c b/src/gdbmshell.c
index d7aa9f1..32c9142 100644
--- a/src/gdbmshell.c
+++ b/src/gdbmshell.c
@@ -25,6 +25,7 @@
 #include <sys/ioctl.h>
 #include <sys/wait.h>
 #include <sys/time.h>
+#include <sys/resource.h>
 #include <termios.h>
 #include <stdarg.h>
 #ifdef HAVE_LOCALE_H
@@ -1591,6 +1592,37 @@ source_handler (struct command_param *param,
   return 0;
 }
 
+static int
+perror_handler (struct command_param *param, struct command_environ *cenv)
+{
+  int n;
+
+  if (param->argc)
+    {
+      if (getnum (&n, PARAM_STRING (param, 0), NULL))
+	return 1;
+    }
+  else if (checkdb ())
+    {
+      return 1;
+    }
+  else
+    {
+      n = gdbm_last_errno (gdbm_file);
+    }
+  fprintf (cenv->fp, "GDBM error code %d: \"%s\"\n", n, gdbm_strerror (n));
+  if (gdbm_check_syserr (n))
+    {
+      if (param->argc)
+	fprintf (cenv->fp, "Examine errno.\n");
+      else
+	fprintf (cenv->fp, "System error code %d: \"%s\"\n",
+		 gdbm_last_syserr (gdbm_file),
+		 strerror (gdbm_last_syserr (gdbm_file)));
+    }
+  return 0;
+}
+
 struct history_param
 {
   int from;
@@ -1934,7 +1966,14 @@ static struct command command_tab[] = {
     { { NULL } },
     TRUE,
     REPEAT_NEVER,
-    N_("invoke the shell") },          
+    N_("invoke the shell") },
+  { S(perror), T_CMD,
+    NULL, perror_handler, NULL,
+    { { "[CODE]", GDBM_ARG_STRING },
+      { NULL } },
+    TRUE,
+    REPEAT_NEVER,
+    N_("describe GDBM error code") },
 #undef S
   { NULL }
 };
@@ -2426,10 +2465,6 @@ run_last_command (void)
   return 0;
 }
 
-#define DIFFTIME(now,then)\
-  (((now).tv_sec - (then).tv_sec) \
-   + ((double)((now).tv_usec - (then).tv_usec))/1000000)
-
 static void
 format_arg (struct gdbmarg *arg, struct argdef *def, FILE *fp)
 {
@@ -2472,6 +2507,52 @@ format_arg (struct gdbmarg *arg, struct argdef *def, FILE *fp)
       }
     }
 }  
+
+struct timing
+{
+  struct timeval real;
+  struct timeval user;
+  struct timeval sys;
+};
+
+void
+timing_start (struct timing *t)
+{
+  struct rusage r;
+  gettimeofday (&t->real, NULL);
+  getrusage (RUSAGE_SELF, &r);
+  t->user  = r.ru_utime;
+  t->sys = r.ru_stime;
+}
+
+static inline struct timeval
+timeval_sub (struct timeval a, struct timeval b)
+{
+  struct timeval diff;
+
+  diff.tv_sec = a.tv_sec - b.tv_sec;
+  diff.tv_usec = a.tv_usec - b.tv_usec;
+  if (diff.tv_usec < 0)
+    {
+      --diff.tv_sec;
+      diff.tv_usec += 1000000;
+    }
+
+  return diff;
+}
+
+void
+timing_stop (struct timing *t)
+{	   
+  struct rusage r;
+  struct timeval now;
+  
+  gettimeofday (&now, NULL);
+  getrusage (RUSAGE_SELF, &r);
+  t->real = timeval_sub (now, t->real);
+  t->user = timeval_sub (r.ru_utime, t->user);
+  t->sys = timeval_sub (r.ru_stime, t->sys);
+}
 
 int
 run_command (struct command *cmd, struct gdbmarglist *arglist)
@@ -2485,7 +2566,7 @@ run_command (struct command *cmd, struct gdbmarglist *arglist)
   struct command_param param = HANDLER_PARAM_INITIALIZER;
   struct command_environ cenv = COMMAND_ENVIRON_INITIALIZER;
   int rc = 0;
-  struct timeval start, stop;
+  struct timing tm;
   
   variable_get ("pager", VART_STRING, (void**) &pager);
   
@@ -2548,19 +2629,19 @@ run_command (struct command *cmd, struct gdbmarglist *arglist)
   
   if (variable_is_true ("trace"))
     {
-      fprintf (stdout, "+ %s", cmd->name);
+      fprintf (stderr, "+ %s", cmd->name);
       for (i = 0; i < param.argc; i++)
 	{
-	  format_arg (param.argv[i], &cmd->args[i], stdout);
+	  format_arg (param.argv[i], &cmd->args[i], stderr);
 	}
 
       if (param.vararg)
 	{
 	  struct gdbmarg *arg;
 	  for (arg = param.vararg; arg; arg = arg->next)
-	    format_arg (arg, NULL, stdout);
+	    format_arg (arg, NULL, stderr);
 	}
-      fputc ('\n', stdout);
+      fputc ('\n', stderr);
     }
   
   expected_lines = 0;
@@ -2584,9 +2665,9 @@ run_command (struct command *cmd, struct gdbmarglist *arglist)
       else
 	cenv.fp = stdout;
 
-      gettimeofday (&start, NULL);
+      timing_start (&tm);
       rc = cmd->handler (&param, &cenv);
-      gettimeofday (&stop, NULL);
+      timing_stop (&tm);
       if (cmd->end)
 	cmd->end (cenv.data);
       else if (cenv.data)
@@ -2594,8 +2675,11 @@ run_command (struct command *cmd, struct gdbmarglist *arglist)
 
       if (variable_is_true ("timing"))
 	{
-	  double t = DIFFTIME (stop, start);
-	  fprintf (cenv.fp, "[%s t=%0.9f]\n", cmd->name, t);	  
+	  fprintf (cenv.fp, "[%s r=%lu.%06lu u=%lu.%06lu s=%lu.%06lu]\n",
+		   cmd->name,
+		   tm.real.tv_sec, tm.real.tv_usec,
+		   tm.user.tv_sec, tm.user.tv_usec,
+		   tm.sys.tv_sec, tm.sys.tv_usec);
 	}
       
       if (pagfp)
diff --git a/src/gdbmtool.c b/src/gdbmtool.c
index e8ca9aa..512dd88 100644
--- a/src/gdbmtool.c
+++ b/src/gdbmtool.c
@@ -105,6 +105,8 @@ struct gdbm_option optab[] = {
     N_("open database at the given file descriptor") },
   { 'x', "extended",   NULL,       N_("extended format (numsync)") },
   {   0, "numsync",    NULL,       NULL, PARSEOPT_ALIAS },
+  { 't', "trace",      NULL,       N_("enable trace mode") },
+  { 'T', "timing",     NULL,       N_("print timing after each command") },
 #if GDBMTOOL_DEBUG    
   { OPT_LEX_TRACE, "lex-trace", NULL, N_("enable lexical analyzer traces") },
   { OPT_GRAM_TRACE, "gram-trace", NULL, N_("enable grammar traces") },
@@ -192,6 +194,16 @@ gdbmtool_init (void *data, instream_t *pinstr)
 	variable_set ("filename", VART_STRING, optarg);
 	break;
 
+      case 't':
+	bv = 1;
+	variable_set ("trace", VART_BOOL, &bv);
+	break;
+
+      case 'T':
+	bv = 1;
+	variable_set ("timing", VART_BOOL, &bv);
+	break;
+	
       case 'q':
 	bv = 1;
 	variable_set ("quiet", VART_BOOL, &bv);