apk: improve progress bar

 * make it as wide as the screen
 * make sure it's drawn after package change
 * and draw it using ansi escapes in line buffered stderr

src/apk.c

@@ -19,6 +19,7 @@
 #include <getopt.h>
 #include <unistd.h>
 #include <sys/stat.h>
+#include <sys/ioctl.h>
 
 #include <openssl/crypto.h>
 #ifndef OPENSSL_NO_ENGINE
@@ -32,6 +33,7 @@
 #include "apk_print.h"
 
 char **apk_argv;
+int apk_screen_width;
 
 static struct apk_option generic_options[] = {
 	{ 'h', "help",		"Show generic help or applet specific help" },
@@ -238,6 +240,20 @@ static void init_openssl(void)
 #endif
 }
 
+static void setup_terminal(void)
+{
+	struct winsize w;
+
+	setvbuf(stderr, NULL, _IOLBF, BUFSIZ);
+	if (ioctl(STDERR_FILENO,TIOCGWINSZ, &w) == 0)
+		apk_screen_width = w.ws_col;
+	else
+		apk_screen_width = 70;
+	if (isatty(STDOUT_FILENO) && isatty(STDERR_FILENO) && isatty(STDIN_FILENO))
+		apk_flags |= APK_PROGRESS;
+
+}
+
 int main(int argc, char **argv)
 {
 	struct apk_applet *applet;
@@ -257,9 +273,7 @@ int main(int argc, char **argv)
 	list_init(&dbopts.repository_list);
 	apk_atom_init();
 	umask(0);
-
-	if (isatty(STDOUT_FILENO) && isatty(STDERR_FILENO) && isatty(STDIN_FILENO))
-		apk_flags |= APK_PROGRESS;
+	setup_terminal();
 
 	applet = deduce_applet(argc, argv);
 	num_options = ARRAY_SIZE(generic_options) + 1;

src/apk_defines.h

@@ -51,6 +51,7 @@ extern int apk_verbosity;
 extern unsigned int apk_flags;
 extern const char *apk_arch;
 extern char **apk_argv;
+extern int apk_screen_width;
 
 #define APK_FORCE		0x0001
 #define APK_SIMULATE		0x0002

src/state.c

@@ -668,19 +668,19 @@ static void apk_count_change(struct apk_change *change, struct apk_stats *stats)
 		stats->packages ++;
 }
 
-static inline void apk_draw_progress(int percent)
+static void apk_draw_progress(int percent)
 {
-	char tmp[128];
-	char reset[128];
+	const int bar_width = (apk_screen_width - 15);
 	int i;
 
-	snprintf(tmp, sizeof(tmp), "-[                    ]- %3i%%", percent);
-	for (i = 0; (i < (percent/5)) && (i < (sizeof(tmp)-2)); i++)
-		tmp[2+i] = '#';
-	memset(reset, '\b', strlen(tmp));
-	fwrite(tmp, strlen(tmp), 1, stderr);
-	fwrite(reset, strlen(tmp), 1, stderr);
+	fputs("\e7-[", stderr);
+	for (i = 0; i < bar_width * percent / 100; i++)
+		fputc('#', stderr);
+	for (; i < bar_width; i++)
+		fputc(' ', stderr);
+	fprintf(stderr, "]- %3i%%", percent);
 	fflush(stderr);
+	fputs("\e8\e[0K", stderr);
 }
 
 struct progress {
@@ -950,6 +950,8 @@ int apk_state_commit(struct apk_state *state,
 	list_for_each_entry(change, &state->change_list_head, change_list) {
 		n++;
 		apk_print_change(db, change->oldpkg, change->newpkg, n, state->num_changes);
+		if (apk_flags & APK_PROGRESS)
+			apk_draw_progress(prog.count);
 		prog.pkg = change->newpkg;
 
 		if (!(apk_flags & APK_SIMULATE)) {