gawk

commit ffba757836dd113b7c4f858dd1bc7140eb017fc8
parent a1ea8f71d6c75d7a03e21ba6e0ab8da15846bd88
Author: Jacob R. Edwards <jacobouno@protonmail.com>
Date:   Fri,  1 Jan 2021 20:10:35 -0800

Add better signal handling

Create a function to remove temporary files without unwinding the
stack and simply call exit(1) in sighandler. This fixes hanging due
to DNS lookups or recv.

Also bump copywrite year.

Diffstat:
M
config.def.h
 | 
3
---
M
main.c
 | 
55
+++++++++++++++++++++++++++++++++++++++----------------

2 files changed, 39 insertions(+), 19 deletions(-)
diff --git a/config.def.h b/config.def.h
@@ -3,9 +3,6 @@
 /* default gopher hole (path, host, port): */
 static const char *default_address[] = { "/", "localhost", "70" };
 
-/* signals to handle */
-static const int signals[] = { SIGABRT, SIGCHLD, SIGINT, SIGTERM };
-
 #define IFS	":\t "	/* input field seporator */
 #define ISS	";\n"	/* input statement seporator */
 
diff --git a/main.c b/main.c
@@ -1,5 +1,5 @@
 /*  This file is part of gawk to browse gopher servers.
- *  Copyright (C) 2020 Jacob R. Edwards
+ *  Copyright (C) 2020, 2021 Jacob R. Edwards
  *
  *  This program is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -19,6 +19,7 @@
 #include <sys/stat.h>
 #include <sys/wait.h>
 #include <ctype.h>
+#include <dirent.h>
 #include <err.h>
 #include <errno.h>
 #include <libgen.h>
@@ -81,6 +82,16 @@ wfclose(FILE *fp)
 }
 
 int
+wremove(const char *path)
+{
+	if (remove(path)) {
+		warn("unable to remove '%s'", path);
+		return -1;
+	}
+	return 0;
+}
+
+int
 warg(int min, int max, int argc, const char **ap)
 {
 	if (max > 0 && argc > max) {
@@ -686,8 +697,8 @@ gawk(const char **addr)
 		}
 	}
 
-	if (mycache && unlink(cache) == -1)
-		warn("unable to unlink '%s'", cache);
+	if (mycache)
+		wremove(cache);
 	if (feof(stdin))
 		done = depth;
 
@@ -701,22 +712,34 @@ gawk(const char **addr)
 }
 
 void
+cleanup(void)
+{
+	DIR *dir;
+	char path[MY_PATH_MAX];
+	struct dirent *ent;
+
+	dir = opendir(tmpdir);
+	if (dir == NULL)
+		return;	/* ENOTDIR */
+	while ((ent = readdir(dir)) != NULL) {
+		if (ent->d_type == DT_REG) {
+			snprintf(path, sizeof(path), "%s/%s", tmpdir, ent->d_name);
+			wremove(path);
+		}
+	}
+	wremove(tmpdir);
+}
+
+void
 sighandler(int sig)
 {
-	switch (sig) {
-	case SIGCHLD:
-		while (waitpid(WAIT_ANY, NULL, WNOHANG) > 0);
-		break;
-	default:
-		wfclose(stdin);
-		fatal = 1;
-	}
+	cleanup();
+	exit(EXIT_FAILURE);
 }
 
 int
 main(int argc, char *argv[])
 {
-	int i;
 	int status;
 
 	if (argc > 1 && *argv[1] == '-') {
@@ -729,14 +752,14 @@ main(int argc, char *argv[])
 		err(1, "pledge");
 #endif /* __OpenBSD__ */
 
-	for (i = 0; i < LEN(signals); ++i)
-		signal(signals[i], sighandler);
+	signal(SIGCHLD, SIG_IGN);
+	signal(SIGINT, sighandler);
 
 	if (mkdtemp(tmpdir) == NULL)
 		err(1, "mkdtemp '%s'", tmpdir);
 	status = sgoto(argc - 1, (const char **)argv + 1, 0, default_address);
-	if (rmdir(tmpdir) == -1)
-		err(1, "rmdir '%s'", tmpdir);
+	if (wremove(tmpdir) == -1)
+		return 1;
 
 	return status;
 }