1 files changed, 54 insertions, 0 deletions
diff --git a/src/cmd/ps/ps.c b/src/cmd/ps/ps.c
new file mode 100644
index 0000000..76a5841
--- /dev/null
+++ b/src/cmd/ps/ps.c
@@ -0,0 +1,54 @@
+#include <_proc.h>
+#include <ctype.h>
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int
+main(void)
+{
+	char *readbuf = malloc(4096);
+	char *procbuf = malloc(4096);
+	FILE *f = fopen("/proc/", "r");
+	if (!f) {
+		err(1, "couldn't open /proc/");
+	}
+
+	// TODO library for iterating over directories
+	for (;;) {
+		int len = fread(readbuf, 1, 4096, f);
+		if (len <= 0) break;
+		for (int pos = 0; pos < len; ) {
+			char *end = memchr(readbuf + pos, 0, len - pos);
+			if (!end) {
+				errx(1, "unimplemented: buffer overflow");
+			}
+			size_t entryl = end - (readbuf+pos) + 1;
+			if (isdigit(readbuf[pos])) {
+				FILE *g;
+				sprintf(procbuf, "/proc/%smem", readbuf+pos);
+				g = fopen(procbuf, "r");
+				if (!g) {
+					warn("couldn't open \"%s\"", procbuf);
+					strcpy(procbuf, "(can't peek)");
+				} else {
+					fseek(g, (long)&_psdata_loc->desc, SEEK_SET);
+					if (fread(procbuf, 1, 128, g) <= 0) {
+						strcpy(procbuf, "(no psdata)");
+					}
+					procbuf[128] = '\0';
+					fclose(g);
+				}
+				end[-1] = '\0'; /* remove trailing slash */
+				printf("%s\t%s\n", readbuf+pos, procbuf);
+			}
+			pos += entryl;
+		}
+	}
+
+	free(readbuf);
+	free(procbuf);
+	fclose(f);
+	return 0;
+}