From eed328240d04caedfaeef83342cf219758e20ded Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=BD=D0=B0=D0=B1?= <nabijaczleweli@nabijaczleweli.xyz>
Date: Sat, 6 Jul 2024 01:00:30 +0200
Subject: [PATCH] Add \e[ m escape to mark a line. Ctrl+PgUp/+PgDn scroll to
 marked lines

Primarily useful for C++ enthusiasts so if you get a megabyte of errors
you can go back to the first one

Recommended usage: PS1="$PS1\e[ m"

Ref: https://101010.pl/@atax1a@infosec.exchange/112734806523834451
---
 config.def.h |  2 ++
 st.c         | 41 +++++++++++++++++++++++++++++++++++++++++
 st.h         |  3 +++
 3 files changed, 46 insertions(+)

diff --git a/config.def.h b/config.def.h
index fc3079e..5bf8132 100644
--- a/config.def.h
+++ b/config.def.h
@@ -226,7 +226,9 @@ static Shortcut shortcuts[] = {
 	{ ShiftMask,            XK_Insert,      selpaste,       {.i =  0} },
 	{ TERMMOD,              XK_Num_Lock,    numlock,        {.i =  0} },
 	{ ShiftMask,            XK_Page_Up,     kscrollup,      {.i = -1} },
+	{ ControlMask,          XK_Page_Up,     kscrolltoprevmark         },
 	{ ShiftMask,            XK_Page_Down,   kscrolldown,    {.i = -1} },
+	{ ControlMask,          XK_Page_Down,   kscrolltonextmark         },
 	{ TERMMOD,              XK_I,           iso14755,       {.i =  0} },
 };
 
diff --git a/st.c b/st.c
index ddd14c1..353d6c6 100644
--- a/st.c
+++ b/st.c
@@ -1104,6 +1104,44 @@ kscrollup(const Arg* a)
 	}
 }
 
+void
+kscrolltonextmark(const Arg* a)
+{
+	int orig_scr = term.scr;
+
+	while (--term.scr >= 0)
+		if (TLINE(0)->mode & ATTR_MARKED) {
+		found:
+			if (term.scr != orig_scr) {
+				selscroll(0, term.scr - orig_scr);
+				tfulldirt();
+			}
+			return;
+		}
+
+	term.scr = 0;
+	for(int i = 0; i < term.row; ++i)
+		if (TLINE(i)->mode & ATTR_MARKED)
+			goto found;
+
+	term.scr = orig_scr;
+}
+
+void
+kscrolltoprevmark(const Arg* a)
+{
+	int orig_scr = term.scr;
+
+	while (++term.scr <= HISTSIZE)
+		if (TLINE(0)->mode & ATTR_MARKED) {
+			selscroll(0, term.scr - orig_scr);
+			tfulldirt();
+			return;
+		}
+
+	term.scr = orig_scr;
+}
+
 void
 tscrolldown(int orig, int n, int copyhist)
 {
@@ -1881,6 +1919,9 @@ csihandle(void)
 			if (xsetcursor(csiescseq.arg[0]))
 				goto unknown;
 			break;
+		case 'm': /* mark line to quickly scroll back to later */
+			term.line[term.c.y]->mode |= ATTR_MARKED;
+			break;
 		default:
 			goto unknown;
 		}
diff --git a/st.h b/st.h
index 9dba57d..469e5c4 100644
--- a/st.h
+++ b/st.h
@@ -35,6 +35,7 @@ enum glyph_attribute {
 	ATTR_WDUMMY     = 1 << 10,
 	ATTR_BOXDRAW    = 1 << 11,
 	ATTR_BOLD_FAINT = ATTR_BOLD | ATTR_FAINT,
+	ATTR_MARKED     = 1 << 12,
 };
 
 enum selection_mode {
@@ -84,6 +85,8 @@ void draw(void);
 
 void kscrolldown(const Arg *);
 void kscrollup(const Arg *);
+void kscrolltonextmark(const Arg *);
+void kscrolltoprevmark(const Arg *);
 void iso14755(const Arg *);
 void printscreen(const Arg *);
 void printsel(const Arg *);
-- 
2.39.2