libc: implement asprintf

4 files changed, 45 insertions, 30 deletions

diff --git a/src/cmd/find.c b/src/cmd/find.c
index d473b82..8f0352c 100644
--- a/src/cmd/find.c
+++ b/src/cmd/find.c
@@ -1,4 +1,3 @@
-#include <camellia/path.h>
 #include <dirent.h>
 #include <err.h>
 #include <errno.h>
@@ -6,7 +5,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-void recurse(char *path) {
+void recurse(const char *path) {
 	DIR *d = opendir(path);
 	if (!d) {
 		warn("couldn't open %s", path);
@@ -25,31 +24,22 @@ void recurse(char *path) {
 		printf("%s%s\n", path, dent->d_name);
 		/* if the string ends with '/' */
 		if (strchr(dent->d_name, '\0')[-1] == '/') {
-			// TODO no overflow check
-			char *pend = strchr(path, '\0');
-			strcpy(pend, dent->d_name);
-			recurse(path);
-			*pend = '\0';
+			char *next;
+			if (asprintf(&next, "%s%s", path, dent->d_name) >= 0) {
+				recurse(next);
+				free(next);
+			}
 		}
 	}
 	closedir(d);
 }
 
-void find(const char *path) {
-	// TODO bound checking
-	// TODO or just implement asprintf()
-	char *buf = malloc(PATH_MAX);
-	memcpy(buf, path, strlen(path)+1);
-	recurse(buf);
-	free(buf);
-}
-
 int main(int argc, char **argv) {
 	if (argc < 2) {
-		find("/");
+		recurse("/");
 	} else {
 		for (int i = 1; i < argc; i++)
-			find(argv[i]);
+			recurse(argv[i]);
 	}
 	return 0;
 }
diff --git a/src/cmd/ps.c b/src/cmd/ps.c
index c855251..98aab8a 100644
--- a/src/cmd/ps.c
+++ b/src/cmd/ps.c
@@ -19,7 +19,6 @@ main(int argc, const char *argv[])
 	const char *path = argc >= 2 ? argv[1] : "/proc/";
 	if (argc > 2) usage();
 
-	char *procbuf = malloc(4096);
 	DIR *dir = opendir(path);
 	if (!dir) {
 		err(1, "couldn't open %s", path);
@@ -28,27 +27,27 @@ main(int argc, const char *argv[])
 	struct dirent *de;
 	while ((de = readdir(dir))) {
 		const char *name = de->d_name;
-		if (isdigit(name[0])) {
-			FILE *g;
-			sprintf(procbuf, "%s%smem", path, name);
-			g = fopen(procbuf, "r");
+		char psdata[128];
+		char *s;
+		if (isdigit(name[0]) && asprintf(&s, "%s%smem", path, name) >= 0) {
+			FILE *g = fopen(s, "r");
+			free(s);
 			if (!g) {
-				warn("couldn't open \"%s\"", procbuf);
-				strcpy(procbuf, "(can't peek)");
+				warn("couldn't open \"%s\"", s);
+				strcpy(psdata, "(can't peek)");
 			} else {
 				fseek(g, (long)&_psdata_loc->desc, SEEK_SET);
-				if (fread(procbuf, 1, 128, g) <= 0) {
-					strcpy(procbuf, "(no psdata)");
+				if (fread(psdata, 1, sizeof(psdata)-1, g) <= 0) {
+					strcpy(psdata, "(no psdata)");
 				}
-				procbuf[128] = '\0';
+				psdata[sizeof(psdata)-1] = '\0';
 				fclose(g);
 			}
 			*strchr(name, '/') = '\0';
-			printf("%s\t%s\n", name, procbuf);
+			printf("%s\t%s\n", name, psdata);
 		}
 	}
 
-	free(procbuf);
 	closedir(dir);
 	return 0;
 }
diff --git a/src/libc/include/stdio.h b/src/libc/include/stdio.h
index b582e8f..159bdca 100644
--- a/src/libc/include/stdio.h
+++ b/src/libc/include/stdio.h
@@ -28,10 +28,12 @@ int printf(const char *restrict fmt, ...);
 int fprintf(FILE *restrict f, const char *restrict fmt, ...);
 
 int sprintf(char *restrict s, const char *restrict fmt, ...);
+int asprintf(char **restrict sp, const char *restrict fmt, ...);
 int snprintf(char *restrict str, size_t len, const char *restrict fmt, ...);
 
 int vprintf(const char *restrict fmt, va_list ap);
 int vsprintf(char *restrict s, const char *restrict fmt, va_list ap);
+int vasprintf(char **restrict sp, const char *restrict fmt, va_list ap);
 int vfprintf(FILE *restrict f, const char *restrict fmt, va_list ap);
 
 int _klogf(const char *fmt, ...); // for kernel debugging only
diff --git a/src/libc/stdio/asprintf.c b/src/libc/stdio/asprintf.c
new file mode 100644
index 0000000..ee24e38
--- /dev/null
+++ b/src/libc/stdio/asprintf.c
@@ -0,0 +1,24 @@
+#include <shared/mem.h>
+#include <shared/printf.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int asprintf(char **restrict sp, const char *restrict fmt, ...) {
+	int ret;
+	va_list argp;
+	va_start(argp, fmt);
+	ret = vasprintf(sp, fmt, argp);
+	va_end(argp);
+	return ret;
+}
+int vasprintf(char **restrict sp, const char *restrict fmt, va_list ap) {
+	va_list ap2;
+	va_copy(ap2, ap);
+	int ret = vsnprintf(NULL, 0, fmt, ap2);
+	va_end(ap2);
+
+	if (ret < 0) return ret;
+	*sp = malloc(ret+1);
+	if (*sp == NULL) return -1;
+	return vsnprintf(*sp, ret+1, fmt, ap);
+}