Clear the magic number.

src/find/matchers/ls.rs

@@ -14,33 +14,70 @@ use super::{Matcher, MatcherIO};
 
 #[cfg(unix)]
 fn format_permissions(mode: u32) -> String {
-    let file_type = if mode & 0o170000 == 0o040000 {
-        "d"
-    } else if mode & 0o170000 == 0o100000 {
-        "-"
-    } else {
-        "?"
+    let file_type = match mode & uucore::libc::S_IFMT {
+        uucore::libc::S_IFDIR => "d",
+        uucore::libc::S_IFREG => "-",
+        _ => "?",
     };
 
+    // S_$$USR means "user permissions"
     let user_perms = format!(
         "{}{}{}",
-        if mode & 0o0400 != 0 { "r" } else { "-" },
-        if mode & 0o0200 != 0 { "w" } else { "-" },
-        if mode & 0o0100 != 0 { "x" } else { "-" }
+        if mode & uucore::libc::S_IRUSR != 0 {
+            "r"
+        } else {
+            "-"
+        },
+        if mode & uucore::libc::S_IWUSR != 0 {
+            "w"
+        } else {
+            "-"
+        },
+        if mode & uucore::libc::S_IXUSR != 0 {
+            "x"
+        } else {
+            "-"
+        }
     );
 
+    // S_$$GRP means "group permissions"
     let group_perms = format!(
         "{}{}{}",
-        if mode & 0o0040 != 0 { "r" } else { "-" },
-        if mode & 0o0020 != 0 { "w" } else { "-" },
-        if mode & 0o0010 != 0 { "x" } else { "-" }
+        if mode & uucore::libc::S_IRGRP != 0 {
+            "r"
+        } else {
+            "-"
+        },
+        if mode & uucore::libc::S_IWGRP != 0 {
+            "w"
+        } else {
+            "-"
+        },
+        if mode & uucore::libc::S_IXGRP != 0 {
+            "x"
+        } else {
+            "-"
+        }
     );
 
+    // S_$$OTH means "other permissions"
     let other_perms = format!(
         "{}{}{}",
-        if mode & 0o0004 != 0 { "r" } else { "-" },
-        if mode & 0o0002 != 0 { "w" } else { "-" },
-        if mode & 0o0001 != 0 { "x" } else { "-" }
+        if mode & uucore::libc::S_IROTH != 0 {
+            "r"
+        } else {
+            "-"
+        },
+        if mode & uucore::libc::S_IWOTH != 0 {
+            "w"
+        } else {
+            "-"
+        },
+        if mode & uucore::libc::S_IXOTH != 0 {
+            "x"
+        } else {
+            "-"
+        }
     );
 
     format!("{}{}{}{}", file_type, user_perms, group_perms, other_perms)
@@ -50,6 +87,7 @@ fn format_permissions(mode: u32) -> String {
 fn format_permissions(file_attributes: u32) -> String {
     let mut attributes = Vec::new();
 
+    // https://learn.microsoft.com/en-us/windows/win32/fileio/file-attribute-constants
     if file_attributes & 0x0001 != 0 {
         attributes.push("read-only");
     }

src/find/mod.rs

@@ -1317,7 +1317,7 @@ mod tests {
 
         let _ = fs::remove_file("test_data/find_fprint");
     }
-  
+
     #[test]
     #[cfg(unix)]
     fn test_ls() {