dwl port of dwm's environmentvar patch `https://dwm.suckless.org/patches/environmentvars/`

terminal-envvar.patch

From 05befebe956d7e42e540bf86d0a6b938f7573e3c Mon Sep 17 00:00:00 2001
From: tunalad <[email protected]>
Date: Mon, 6 Nov 2023 22:19:07 +0100
Subject: [PATCH] terminal-envvar patch

pretty much clone of dwm's `environmentvars` patch, it loads the name of the terminal emulator to be used as termcmd from the environment variable TERMINAL using getenv(3p).
example: 
```sh
$ export TERMINAL="alacritty"
```
`https://dwm.suckless.org/patches/environmentvars/`
---
 config.def.h | 2 +-
 dwl.c        | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/config.def.h b/config.def.h
index db0babc..bc54005 100644
--- a/config.def.h
+++ b/config.def.h
@@ -112,7 +112,7 @@ static const enum libinput_config_tap_button_map button_map = LIBINPUT_CONFIG_TA
 #define SHCMD(cmd) { .v = (const char*[]){ "/bin/sh", "-c", cmd, NULL } }
 
 /* commands */
-static const char *termcmd[] = { "foot", NULL };
+#define TERMINAL_ENVVAR "TERMINAL"
 static const char *menucmd[] = { "bemenu-run", NULL };
 
 static const Key keys[] = {
diff --git a/dwl.c b/dwl.c
index a7d41b0..6baedbc 100644
--- a/dwl.c
+++ b/dwl.c
@@ -361,6 +361,7 @@ static struct wl_list keyboards;
 static unsigned int cursor_mode;
 static Client *grabc;
 static int grabcx, grabcy; /* client-relative */
+static char * termcmd[] = { NULL, NULL };
 
 static struct wlr_output_layout *output_layout;
 static struct wlr_box sgeom;
@@ -2141,6 +2142,12 @@ setup(void)
 
 	wlr_log_init(log_level, NULL);
 
+	/* load terminal environment variable */
+		termcmd[0] = getenv(TERMINAL_ENVVAR);
+		if (termcmd[0] == NULL) {
+		die("couldn't load " TERMINAL_ENVVAR " environment variable.");
+	}
+
 	/* The Wayland display is managed by libwayland. It handles accepting
 	 * clients from the Unix socket, manging Wayland globals, and so on. */
 	dpy = wl_display_create();
-- 
2.42.0