Userland/ls: escape non-printable characters

Fixes SerenityOS#1044

Userland/ls.cpp

@@ -4,6 +4,7 @@
 #include <AK/StringBuilder.h>
 #include <AK/Vector.h>
 #include <LibCore/CDirIterator.h>
+#include <ctype.h>
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
@@ -121,11 +122,28 @@ int main(int argc, char** argv)
  return status;
 }
 
+int print_escaped(const char* name)
+{
+ int printed = 0;
+
+ for (int i = 0; name[i] != '\0'; i++) {
+ if (isprint(name[i])) {
+ putchar(name[i]);
+ printed++;
+ } else {
+ printed += printf("\\%03d", name[i]);
+ }
+ }
+
+ return printed;
+}
+
 int print_name(const struct stat& st, const String& name, const char* path_for_link_resolution = nullptr)
 {
- int nprinted = name.length();
+ int nprinted = 0;
+
  if (!flag_colorize || !output_is_terminal) {
- printf("%s", name.characters());
+ nprinted = printf("%s", name.characters());
  } else {
  const char* begin_color = "";
  const char* end_color = "\033[0m";
@@ -144,7 +162,9 @@ int print_name(const struct stat& st, const String& name, const char* path_for_l
  begin_color = "\033[35;1m";
  else if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))
  begin_color = "\033[33;1m";
- printf("%s%s%s", begin_color, name.characters(), end_color);
+ printf("%s", begin_color);
+ nprinted = print_escaped(name.characters());
+ printf("%s", end_color);
  }
  if (S_ISLNK(st.st_mode)) {
  if (path_for_link_resolution) {
@@ -153,7 +173,7 @@ int print_name(const struct stat& st, const String& name, const char* path_for_l
  if (nread < 0)
  perror("readlink failed");
  else
- nprinted += printf(" -> %s", linkbuf);
+ nprinted += printf(" -> ") + print_escaped(linkbuf);
  } else {
  nprinted += printf("@");
  }