Add resolve_path util function

common/util.c

@@ -1,3 +1,7 @@
+#define _XOPEN_SOURCE 500
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
 #include <math.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -118,3 +122,32 @@ uint32_t parse_color(const char *color) {
 	}
 	return res;
 }
+
+char* resolve_path(const char* path) {
+    struct stat sb;
+    char *resolved = NULL;
+    ssize_t r;
+
+    if (lstat(path, &sb) == -1) {
+       goto failed;
+    }
+    if(S_ISREG(sb.st_mode)) {
+        return strdup(path);
+    }
+    if (!(resolved = malloc(sb.st_size + 1))) {
+       return NULL;
+    }
+    r = readlink(path, resolved, sb.st_size);
+    if (r == -1) {
+       goto failed;
+    }
+    if (r > sb.st_size) {
+       goto failed;
+    }
+    resolved[r] = '\0';
+
+    return resolved;
+
+failed:
+    return strdup(path);
+}

include/util.h

@@ -49,4 +49,10 @@ pid_t get_parent_pid(pid_t pid);
  */
 uint32_t parse_color(const char *color);
 
+/**
+ * Given a path string, resolves symlinks to their targets and return the result
+ * If the path does not exist or is not a symlink a string copy of it is returned.
+ * Returns NULL on error. Caller must free the returned buffer.
+ */
+char* resolve_path(const char* path);
 #endif