libc: implement asprintf

1 files changed, 11 insertions, 12 deletions

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;
 }