Fix psql \h output for case of no parameters (ie, list all the known commands)

to format properly for the actually needed column width, instead of having
a hard-wired assumption about the longest command name length.  Also make it
respond to the current screen width.  In passing, const-ify the constant
table.

diff --git a/src/bin/psql/create_help.pl b/src/bin/psql/create_help.pl
index f969f9308617c8e2cdd9606666d34dc72b3b7c3d..0fc0f487ce29676609cb00208acc0a7d03bd4834 100644 (file)
--- a/src/bin/psql/create_help.pl
+++ b/src/bin/psql/create_help.pl
@@ -5,7 +5,7 @@
 #
 # Copyright (c) 2000-2008, PostgreSQL Global Development Group
 #
-# $PostgreSQL: pgsql/src/bin/psql/create_help.pl,v 1.16 2008/01/01 19:45:55 momjian Exp $
+# $PostgreSQL: pgsql/src/bin/psql/create_help.pl,v 1.17 2008/01/20 21:13:55 tgl Exp $
 #################################################################
 
 #
@@ -51,20 +51,21 @@ print OUT
 #ifndef $define
 #define $define
 
-#define N_(x) (x) /* gettext noop */
+#define N_(x) (x)              /* gettext noop */
 
 struct _helpStruct
 {
-    char      *cmd;       /* the command name */
-    char      *help;      /* the help associated with it */
-    char      *syntax;    /* the syntax associated with it */
+   const char     *cmd;        /* the command name */
+   const char     *help;       /* the help associated with it */
+   const char     *syntax;     /* the syntax associated with it */
 };
 
 
-static struct _helpStruct QL_HELP[] = {
+static const struct _helpStruct QL_HELP[] = {
 ";
 
 $count = 0;
+$maxlen = 0;
 
 foreach $file (sort readdir DIR) {
     local ($cmdname, $cmddesc, $cmdsynopsis);
@@ -113,7 +114,9 @@ foreach $file (sort readdir DIR) {
         $cmdsynopsis =~ s/\"/\\"/g;
 
    print OUT "    { \"$cmdname\",\n      N_(\"$cmddesc\"),\n      N_(\"$cmdsynopsis\") },\n\n";
-        $count++;
+
+   $count++;
+   $maxlen = ($maxlen >= length $cmdname) ? $maxlen : length $cmdname;
     }
     else {
    print STDERR "$0: parsing file '$file' failed (N='$cmdname' D='$cmddesc')\n";
@@ -125,7 +128,8 @@ print OUT "
 };
 
 
-#define QL_HELP_COUNT $count
+#define QL_HELP_COUNT  $count      /* number of help items */
+#define QL_MAX_CMD_LEN $maxlen     /* largest strlen(cmd) */
 
 
 #endif /* $define */

diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c
index e9f2e0db08659edcb62ac527c6da66be0390ff66..9d0eb40a24a297cf8e37ad434dfd36f8d0e20c8a 100644 (file)
--- a/src/bin/psql/help.c
+++ b/src/bin/psql/help.c
@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2008, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/help.c,v 1.121 2008/01/01 19:45:56 momjian Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/help.c,v 1.122 2008/01/20 21:13:55 tgl Exp $
  */
 #include "postgres_fe.h"
 
@@ -19,6 +19,14 @@
 #include 
 #endif
 
+#ifndef WIN32
+#include          /* for ioctl() */
+#endif
+
+#ifdef HAVE_TERMIOS_H
+#include 
+#endif
+
 #include "pqsignal.h"
 
 #include "common.h"
@@ -147,15 +155,6 @@ usage(void)
  *
  * print out help for the backslash commands
  */
-
-#ifndef TIOCGWINSZ
-struct winsize
-{
-   int         ws_row;
-   int         ws_col;
-};
-#endif
-
 void
 slashUsage(unsigned short int pager)
 {
@@ -280,24 +279,46 @@ helpSQL(const char *topic, unsigned short int pager)
 
    if (!topic || strlen(topic) == 0)
    {
-       int         i;
-       int         items_per_column = (QL_HELP_COUNT + 2) / 3;
+       /* Print all the available command names */
+       int         screen_width;
+       int         ncolumns;
+       int         nrows;
        FILE       *output;
+       int         i;
+       int         j;
 
-       output = PageOutput(items_per_column + 1, pager);
+#ifdef TIOCGWINSZ
+       struct winsize screen_size;
+
+       if (ioctl(fileno(stdout), TIOCGWINSZ, &screen_size) == -1)
+           screen_width = 80;  /* ioctl failed, assume 80 */
+       else
+           screen_width = screen_size.ws_col;
+#else
+       screen_width = 80;      /* default assumption */
+#endif
+
+       ncolumns = (screen_width - 3) / (QL_MAX_CMD_LEN + 1);
+       ncolumns = Max(ncolumns, 1);
+       nrows = (QL_HELP_COUNT + (ncolumns - 1)) / ncolumns;
+
+       output = PageOutput(nrows + 1, pager);
 
        fputs(_("Available help:\n"), output);
 
-       for (i = 0; i < items_per_column; i++)
+       for (i = 0; i < nrows; i++)
        {
-           fprintf(output, "  %-26s%-26s",
-                   VALUE_OR_NULL(QL_HELP[i].cmd),
-                   VALUE_OR_NULL(QL_HELP[i + items_per_column].cmd));
-           if (i + 2 * items_per_column < QL_HELP_COUNT)
-               fprintf(output, "%-26s",
-                       VALUE_OR_NULL(QL_HELP[i + 2 * items_per_column].cmd));
+           fprintf(output, "  ");
+           for (j = 0; j < ncolumns-1; j++)
+               fprintf(output, "%-*s",
+                       QL_MAX_CMD_LEN + 1,
+                       VALUE_OR_NULL(QL_HELP[i + j * nrows].cmd));
+           if (i + j * nrows < QL_HELP_COUNT)
+               fprintf(output, "%s",
+                       VALUE_OR_NULL(QL_HELP[i + j * nrows].cmd));
            fputc('\n', output);
        }
+
        /* Only close if we used the pager */
        if (output != stdout)
        {
@@ -317,7 +338,7 @@ helpSQL(const char *topic, unsigned short int pager)
        size_t      len,
                    wordlen;
        int         nl_count = 0;
-       char       *ch;
+       const char *ch;
 
        /* User gets two chances: exact match, then the first word */