Add process searching

jni/utils/misc.c

@@ -4,6 +4,11 @@
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include <sys/types.h>
 
 #include "utils.h"
 
@@ -34,3 +39,72 @@ void file_to_vector(struct vector *v, FILE *fp) {
 		line = NULL;
 	}
 }
+
+/* Check if the string only contains digits */
+int isNum(const char *s) {
+	int len = strlen(s);
+	for (int i = 0; i < len; ++i)
+		if (s[i] < '0' || s[i] > '9')
+			return 0;
+	return 1;
+}
+
+/* Read a whole line from file descriptor */
+ssize_t fdreadline(int fd, char *buf, size_t size) {
+	ssize_t read = 0;
+	buf[0] = '\0';
+	while (xread(fd, buf + read, 1)) {
+		if (buf[read] == '\n')
+			buf[read] = '\0';
+		if (buf[read++] == '\0')
+			break;
+		if (read == size) {
+			buf[read - 1] = '\0';
+			break;
+		}
+	}
+	return read;
+}
+
+/* Call func for each process */
+void ps(void (*func)(int)) {
+	DIR *dir;
+	struct dirent *entry;
+
+	dir = xopendir("/proc");
+
+	while ((entry = xreaddir(dir))) {
+		if (entry->d_type == DT_DIR) {
+			if (isNum(entry->d_name))
+				func(atoi(entry->d_name));
+		}
+	}
+	
+	closedir(dir);
+}
+
+// Internal usage
+static void (*ps_filter_cb)(int);
+static const char *ps_filter_pattern;
+static void proc_name_filter(int pid) {
+	char buf[64];
+	snprintf(buf, sizeof(buf), "/proc/%d/cmdline", pid);
+	int fd = xopen(buf, O_RDONLY);
+	if (fdreadline(fd, buf, sizeof(buf)) == 0) {
+		snprintf(buf, sizeof(buf), "/proc/%d/comm", pid);
+		close(fd);
+		fd = xopen(buf, O_RDONLY);
+		fdreadline(fd, buf, sizeof(buf));
+	}
+	if (strstr(buf, ps_filter_pattern)) {
+		ps_filter_cb(pid);
+	}
+	close(fd);
+}
+
+/* Call func with process name filtered with pattern */
+void ps_filter_proc_name(const char *pattern, void (*func)(int)) {
+	ps_filter_cb = func;
+	ps_filter_pattern = ((pattern == NULL) ? "" : pattern);
+	ps(proc_name_filter);
+}