Fix #11455 - Implement internal less pager with scr.pager=.. (#11548)

* Use full screen in r_cons_less (last line was not used before)

libr/config/config.c

@@ -1,4 +1,4 @@
-/* radare - LGPL - Copyright 2006-2016 - pancake */
+/* radare - LGPL - Copyright 2006-2018 - pancake */
 
 #include "r_config.h"
 #include "r_util.h" // r_str_hash, r_str_chop, ...

libr/cons/cons.c

@@ -44,7 +44,7 @@ static void cons_stack_free(void *ptr) {
 	free (s->buf);
 	if (s->grep) {
 		R_FREE (s->grep->str);
-		I.context->grep.str = NULL;
+		CTX(grep.str) = NULL;
 	}
 	free (s->grep);
 	free (s);
@@ -56,10 +56,10 @@ static RConsStack *cons_stack_dump(bool recreate) {
 		return NULL;
 	}
 
-	if (I.context->buffer) {
-		data->buf = I.context->buffer;
-		data->buf_len = I.context->buffer_len;
-		data->buf_size = I.context->buffer_sz;
+	if (CTX (buffer)) {
+		data->buf = CTX (buffer);
+		data->buf_len = CTX (buffer_len);
+		data->buf_size = CTX (buffer_sz);
 	}
 
 	data->grep = R_NEW0 (RConsGrep);
@@ -109,6 +109,7 @@ static void cons_context_init(RConsContext *context) {
 	context->break_stack = r_stack_newf (6, break_stack_free);
 	context->event_interrupt = NULL;
 	context->event_interrupt_data = NULL;
+	context->pageable = true;
 }
 
 static void cons_context_deinit(RConsContext *context) {
@@ -552,7 +553,7 @@ R_API void r_cons_reset_colors() {
 }
 
 R_API void r_cons_clear() {
-	r_cons_strcat (Color_RESET"\x1b[2J");
+	r_cons_strcat (Color_RESET R_CONS_CLEAR_SCREEN);
 	I.lines = 0;
 }
 
@@ -575,6 +576,7 @@ R_API void r_cons_reset() {
 	I.lines = 0;
 	I.lastline = I.context->buffer;
 	cons_grep_reset (&I.context->grep);
+	CTX (pageable) = true;
 }
 
 R_API const char *r_cons_get_buffer() {
@@ -727,13 +729,21 @@ R_API void r_cons_flush(void) {
 		CTX (lastMode) = false;
 	}
 	r_cons_filter ();
-
 	if (I.is_interactive && I.fdout == 1) {
 		/* Use a pager if the output doesn't fit on the terminal window. */
-		if (I.pager && *I.pager && I.context->buffer_len > 0 && r_str_char_count (I.context->buffer, '\n') >= I.rows) {
+		if (CTX (pageable) && CTX (buffer) && I.pager && *I.pager && CTX (buffer_len) > 0 && r_str_char_count (CTX (buffer), '\n') >= I.rows) {
 			I.context->buffer[I.context->buffer_len - 1] = 0;
-			r_sys_cmd_str_full (I.pager, I.context->buffer, NULL, NULL, NULL);
-			r_cons_reset ();
+			if (!strcmp (I.pager, "..")) {
+				char *str = r_str_ndup (CTX (buffer), CTX (buffer_len));
+				CTX (pageable) = false;
+				r_cons_less_str (str, NULL);
+				r_cons_reset ();
+				free (str);
+				return;
+			} else {
+				r_sys_cmd_str_full (I.pager, CTX (buffer), NULL, NULL, NULL);
+				r_cons_reset ();
+			}
 		} else if (I.context->buffer_len > CONS_MAX_USER) {
 #if COUNT_LINES
 			int i, lines = 0;

libr/cons/less.c

@@ -60,9 +60,13 @@ static void printpage (const char *line, int *index, RList **mla, int from, int
 		color_line (line + index[i], p, mla[i]);
 		r_strpool_ansi_chop (p, w);
 		r_cons_reset_colors ();
-		r_cons_println (p->str);
+		if (i + 1 == to) {
+			r_cons_print (p->str);
+		} else {
+			r_cons_println (p->str);
+		}
 	}
-	r_strpool_free(p);
+	r_strpool_free (p);
 	r_cons_flush ();
 }
 
@@ -219,7 +223,7 @@ R_API int r_cons_less_str(const char *str, const char *exitkeys) {
 	w = h = 0;
 	while (ui) {
 		w = r_cons_get_size (&h);
-		to = R_MIN (lines_count, from + h - 1);
+		to = R_MIN (lines_count, from + h);
 		if (from + 3 > lines_count) {
 			from = lines_count - 3;
 		}
@@ -258,7 +262,7 @@ R_API int r_cons_less_str(const char *str, const char *exitkeys) {
 			break;
 		case ' ': from += h; break;
 		case 'g': from = 0; break;
-		case 'G': from = lines_count-1-h; break;
+		case 'G': from = lines_count-h; break;
 		case -1: // EOF
 		case 'q': ui = 0; break;
 		case '\r':

libr/core/cconfig.c

@@ -1642,9 +1642,13 @@ static int cb_scr_color_grep(void *user, void *data) {
 static int cb_pager(void *user, void *data) {
 	RCore *core = (RCore *) user;
 	RConfigNode *node = (RConfigNode *) data;
-
+	if (!strcmp (node->value, "?")) {
+		eprintf ("Usage: scr.pager must be '..' for internal less, or the path to a program in $PATH");
+		return false;
+	}
 	/* Let cons know we have a new pager. */
-	core->cons->pager = node->value;
+	free (core->cons->pager);
+	core->cons->pager = strdup (node->value);
 	return true;
 }
 
@@ -2895,7 +2899,7 @@ R_API int r_core_config_init(RCore *core) {
 	n = NODECB ("scr.nkey", "flag", &cb_scrnkey);
 	SETDESC (n, "Select visual seek mode (affects n/N visual commands)");
 	SETOPTIONS (n, "fun", "hit", "flag", NULL);
-	SETCB ("scr.pager", "", &cb_pager, "Select pager program (when output overflows the window)");
+	SETCB ("scr.pager", "", &cb_pager, "System program (or '..') to use when output exceeds screen boundaries");
 	SETPREF ("scr.randpal", "false", "Random color palete or just get the next one from 'eco'");
 	SETCB ("scr.color.grep", "false", &cb_scr_color_grep, "Enable colors when using ~grep");
 	SETPREF ("scr.pipecolor", "false", "Enable colors when using pipes");

libr/core/cmd.c

@@ -1608,6 +1608,7 @@ static int cmd_last(void *data, const char *input) {
 	default:
 		eprintf ("Usage: _  print last output\n");
 	}
+	return 0;
 }
 
 static int cmd_system(void *data, const char *input) {

libr/core/cmd_eval.c

@@ -558,7 +558,9 @@ static int cmd_eval(void *data, const char *input) {
 			eprintf ("Usage: er [key]\n");
 		}
 		break;
-	case ' ': r_config_eval (core->config, input+1); break;
+	case ' ':
+		r_config_eval (core->config, input + 1);
+		break;
 	}
 	return 0;
 }

libr/include/r_cons.h

@@ -399,6 +399,7 @@ typedef struct r_cons_context_t {
 	int lastLength;
 	bool lastMode;
 	bool lastEnabled;
+	bool pageable;
 } RConsContext;
 
 typedef struct r_cons_t {
@@ -500,6 +501,7 @@ typedef struct r_cons_t {
 #define R_CONS_KEY_ESC 0x1b
 
 #define R_CONS_CLEAR_LINE "\x1b[2K\r"
+#define R_CONS_CLEAR_SCREEN "\x1b[2J\r"
 
 #define Color_BLINK        "\x1b[5m"
 #define Color_INVERT       "\x1b[7m"

shlr/gdb/include/gdbclient/commands.h

@@ -46,7 +46,7 @@ int gdbr_check_vcont(libgdbr_t *g);
  * remote target's interpreter.
  * \returns 0 on success and -1 on failure
  */
-int gdbr_send_qRcmd(libgdbr_t *g, const char *cmd, void (*cb_printf) (const char *, ...));
+int gdbr_send_qRcmd(libgdbr_t *g, const char *cmd, PrintfCallback cb_printf);
 
 /*!
  * \brief attaches to a process

shlr/gdb/src/gdbclient/core.c

@@ -1186,7 +1186,7 @@ void gdbr_invalidate_reg_cache() {
 	reg_cache.valid = false;
 }
 
-int gdbr_send_qRcmd(libgdbr_t *g, const char *cmd, void (*cb_printf) (const char *fmt, ...)) {
+int gdbr_send_qRcmd(libgdbr_t *g, const char *cmd, PrintfCallback cb_printf) {
 	if (!g || !cmd) {
 		return -1;
 	}