gawk

commit ad8003e6580c65dff0411539d4d4a3fb16a653a0
parent bd3e341b2ef355e6f25e97c1478e7227202f52ff
Author: Jacob R. Edwards <jacobouno@protonmail.com>
Date:   Tue, 22 Dec 2020 02:15:31 -0800

Fix stack overflow and add depth to prompt

I was allocating far too much memory before which, on my system,
generally caused a segmentation fault at eight recursions. With
these smaller (on my system) but still very comfortable limits I
am able to recurse 4800 times safely.

Diffstat:
M
main.c
 | 
44
++++++++++++++++++++++++--------------------

1 file changed, 24 insertions(+), 20 deletions(-)
diff --git a/main.c b/main.c
@@ -32,11 +32,15 @@
 
 #define LEN(X) (sizeof(X) / sizeof(*X))
 
-#define BUFSIZE   4096
-#define ARGV_MAX  16
+#define BUFSIZE   128
 #define ARG_SEP   ":\t "
 #define CMD_SEP   ";\n"
-#define URL_MAX   128
+
+#define MY_ARGV_MAX	12
+#define MY_INPUT_MAX	128	/* MAX_INPUT */
+#define MY_LINE_MAX	128
+#define MY_PATH_MAX	128	/* NOTE: PATH_MAX should be used with realpath(1), etc. */
+#define MY_URL_MAX	72
 
 enum gphitem { GI_INFO, GI_PATH, GI_HOST, GI_PORT, GI_NULL };
 
@@ -132,13 +136,13 @@ strtorange(unsigned int *r, unsigned int min, unsigned int max, const char *s)
 void
 newpath(char *path, const char *newpath)
 {
-	char tmp[PATH_MAX];
+	char tmp[MY_PATH_MAX];
 
 	if (*newpath == '/') {
-		strlcpy(path, newpath, PATH_MAX);
+		strlcpy(path, newpath, MY_PATH_MAX);
 	} else {
-		snprintf(tmp, PATH_MAX, "%s/%s", path, newpath);
-		strlcpy(path, tmp, PATH_MAX);
+		snprintf(tmp, MY_PATH_MAX, "%s/%s", path, newpath);
+		strlcpy(path, tmp, MY_PATH_MAX);
 	}
 }
 
@@ -207,7 +211,7 @@ input(char *buf, int size, const char *delims, const char *prompt, FILE *fp)
 {
 	int next;
 	static int len;
-	static char bb[ARG_MAX];
+	static char bb[MY_INPUT_MAX];
 
 	if (len <= 0) {
 		putprompt(prompt);
@@ -322,7 +326,7 @@ int
 findex(const char *cache, int argc, const char **argv, command *func)
 {
 	FILE *fp;
-	char buf[LINE_MAX];
+	char buf[MY_LINE_MAX];
 	int more;
 	unsigned int i, j;
 	unsigned int indexes[argc];
@@ -360,7 +364,7 @@ int
 fstrmatch(const char *cache, int argc, const char **argv, command *func)
 {
 	FILE *fp;
-	char buf[LINE_MAX];
+	char buf[MY_LINE_MAX];
 	int anystr;
 	int i;
 
@@ -386,7 +390,7 @@ int
 fgroup(const char *cache, int argc, const char **argv, command *func)
 {
 	FILE *fp;
-	char buf[LINE_MAX];
+	char buf[MY_LINE_MAX];
 	int anytype;
 	int i;
 
@@ -416,7 +420,7 @@ int
 sgoto(int argc, const char **argv, int depth, const char *host,
      const char *port, const char *path)
 {
-	char npath[PATH_MAX];
+	char npath[MY_PATH_MAX];
 	const char *nhost, *nport;
 
 	wunused(3, argc, argv);
@@ -505,7 +509,7 @@ cfetch(int argc, const char **argv, int i, const char **request)
 int
 cextern(int argc, const char **argv, int index, const char **item)
 {
-	char url[URL_MAX];
+	char url[MY_URL_MAX];
 	int i;
 
 	if (argc == 0) {
@@ -620,20 +624,20 @@ invalid_statement:
 void
 getcache(char *cache, const char *host, const char *port, const char *path)
 {
-	char tmp[PATH_MAX];
+	char tmp[MY_PATH_MAX];
 
-	strlcpy(tmp, path, PATH_MAX);
+	strlcpy(tmp, path, MY_PATH_MAX);
 	tr(tmp, '/', '-');
-	snprintf(cache, PATH_MAX, "%s/%s-%s-%s", tmpdir, host, port, tmp);
+	snprintf(cache, MY_PATH_MAX, "%s/%s-%s-%s", tmpdir, host, port, tmp);
 }
 
 int
 gawk(const char *host, const char *path, const char *port)
 {
 	static int depth;
-	char *argv[ARGV_MAX];
-	char cache[PATH_MAX];
-	char inbuf[ARG_MAX];
+	char *argv[MY_ARGV_MAX];
+	char cache[MY_PATH_MAX];
+	char inbuf[MY_INPUT_MAX];
 	char prompt[64];
 	int argc;
 	int done;
@@ -652,7 +656,7 @@ gawk(const char *host, const char *path, const char *port)
 	++depth;
 
 	done = 0;
-	snprintf(prompt, sizeof(prompt), "[%s] %s ", host, path);
+	snprintf(prompt, sizeof(prompt), "(%d) [%s] %s ", depth, host, path);
 	while (!done && input(inbuf, sizeof(inbuf), CMD_SEP, prompt, stdin) == 0) {
 		argc = argsplit(argv, LEN(argv), inbuf, ARG_SEP);
 		if (argc < 0) {