Initial commit.

Single file with the whole implementation. Keypad interaction is still
murky; how exactly do I read a backspace or Ctrl+W command?

.gitignore

@@ -0,0 +1,4 @@
+*
+!*.c
+!*.h
+!Makefile

LICENSE

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+Copyright (c) 2021 Érico Nogueira
+
+Permission to use, copy, modify, and distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

Makefile

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+SRC = browser.c
+EXE = browser
+CFLAGS = -Wall -Wextra
+LDLIBS = -lcurses
+
+all: $(EXE)
+
+clean:
+	rm -f $(EXE)

browser.c

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+#define _XOPEN_SOURCE 700
+#include <stdlib.h>
+#include <signal.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include <curses.h>
+
+enum my_keycodes {
+	MY_CTRLW = 7000,
+};
+
+static void endwin_void(void)
+{
+	endwin();
+}
+
+static void finish(int sig)
+{
+	(void)sig;
+	quick_exit(1);
+}
+
+struct str_array {
+	const char **v;
+	bool *m;
+	size_t n, c;
+};
+
+static void add_entry(struct str_array *a, const char *s)
+{
+	if (a->n == a->c) {
+		if (a->c == 0) a->c = 32;
+		else a->c *= 2;
+		a->v = realloc(a->v, sizeof(*a->v) * a->c);
+		a->m = realloc(a->m, sizeof(*a->m) * a->c);
+		if (!a->v || !a->m) {
+			perror("realloc");
+			exit(1);
+		}
+	}
+
+	a->v[a->n] = s;
+	a->m[a->n] = false;
+	a->n++;
+}
+
+static inline const char *get_entry(const struct str_array *a, size_t i)
+{
+	return a->v[i];
+}
+
+static inline const char *get_entry_match(const struct str_array *a, size_t i)
+{
+	return a->m[i] ? a->v[i] : NULL;
+}
+
+static void filter_entries(struct str_array *a, const char *s)
+{
+	for (size_t i = 0; i < a->n; i++) {
+		a->m[i] = strstr(a->v[i], s);
+	}
+}
+
+static void print_entries(const struct str_array *a)
+{
+	for (size_t i = 0; i < a->n; i++) {
+		printf("entry %zu: %s\n", i, get_entry(a, i));
+	}
+}
+
+int main()
+{
+	signal(SIGINT, finish);
+	atexit(endwin_void);
+	at_quick_exit(endwin_void);
+
+	char delim = '\n';
+
+	struct str_array entries = { 0 };
+
+	char *line = NULL;
+	size_t tmp = 0;
+	{
+		ssize_t n;
+		while ((n = getdelim(&line, &tmp, delim, stdin)) >= 0) {
+			if (line[n-1] == '\n') line[n-1] = 0;
+			add_entry(&entries, line);
+
+			line = NULL;
+			tmp = 0;
+		}
+		if (dup2(STDERR_FILENO, STDIN_FILENO) != STDIN_FILENO) {
+			perror("dup2");
+			exit(1);
+		}
+	}
+
+	initscr();
+	nonl();
+	cbreak();
+	noecho();
+
+	if (has_colors()) {
+		start_color();
+		init_pair(1, COLOR_GREEN, COLOR_BLACK);
+		// red,green,yellow,blue,cyan,magenta,white
+	}
+	attrset(COLOR_PAIR(1));
+
+	WINDOW *list = newwin(LINES - 1, 0, 0, 0);
+	WINDOW *prompt = newwin(1, 0, LINES - 1, 0);
+	if (!list || !prompt) {
+		perror("newwin");
+		exit(1);
+	}
+	keypad(prompt, TRUE);
+	keypad(list, TRUE);
+
+	for (size_t i = 0; i < entries.n; i++) {
+		mvwaddstr(list, i, 0, get_entry(&entries, i));
+	}
+	wrefresh(list);
+
+	mvwaddstr(prompt, 0, 0, "> ");
+	wrefresh(prompt);
+
+	char name[1024] = { 0 };
+	size_t n = 0;
+	while (n < sizeof name) {
+		int c = wgetch(prompt);
+		switch (c) {
+			case KEY_BACKSPACE:
+			case 127:
+				name[n] = 0;
+				if (n) n--;
+				break;
+			case KEY_DL:
+				name[0] = 0;
+				n = 0;
+				break;
+			default:
+				name[n] = c;
+				n++;
+				break;
+		}
+		werase(prompt);
+		mvwaddstr(prompt, 0, 0, "> ");
+		waddstr(prompt, name);
+		wrefresh(prompt);
+		filter_entries(&entries, name);
+
+		werase(list);
+		int line = 0;
+		for (size_t i = 0; i < entries.n; i++) {
+			const char *e = get_entry_match(&entries, i);
+			if (e) mvwaddstr(list, line++, 0, e);
+		}
+		wrefresh(list);
+	}
+
+	return 0;
+}