doc: try to make it dir-depth agnostic

Still ironing out some problems

.gitignore

@@ -1 +1,2 @@
+*.swp
 target

src/doc.rs

@@ -1,5 +1,6 @@
 use std::env;
 use std::fs::File;
+use std::path::PathBuf;
 use std::io::prelude::*;
 use std::io::BufReader;
 use regex::Regex;
@@ -131,7 +132,10 @@ fn process_template<T: Read>(template: &mut T,
 }
 
 fn get_crate_info() -> Result<CrateInfo, String> {
-    let current_dir = env::current_dir().unwrap();
+    let current_dir = match project_root_dir() {
+        Some(v) => v,
+        None => return Err("Not in a rust project".into()),
+    };
 
     let mut cargo_toml = match File::open(current_dir.join("Cargo.toml")) {
         Ok(file) => file,
@@ -193,3 +197,23 @@ fn append_license(readme: String, license: &str) -> String {
 
     new_readme
 }
+
+/// Given the current directory, start from there, and go up, and up, until a Cargo.toml file has
+/// been found. If a Cargo.toml folder has been found, then we have found the project dir. If not,
+/// nothing is found, and we return None.
+pub fn project_root_dir() -> Option<PathBuf> {
+    let mut currpath= env::current_dir().unwrap();
+
+    while currpath.parent().is_some() {
+        currpath.push("Cargo.toml");
+        if currpath.is_file() {
+            currpath.pop(); // found, remove toml, return project root
+            println!("return : {:?}", currpath);
+            return Some(currpath);
+        }
+        currpath.pop(); // remove toml filename
+        currpath.pop(); // next dir
+    }
+
+    None
+}

src/main.rs

@@ -89,17 +89,20 @@
 //!
 //! You can override the displaying of your crate's name and license using `{{crate}}`
 //! and `{{license}}`.
+
+#![feature(path_ext)]
+
 #[macro_use]
 extern crate clap;
 extern crate toml;
 extern crate regex;
 
 mod doc;
 
-use std::env;
 use std::io::{Write, ErrorKind};
-use std::fs::File;
+use std::fs::{File};
 use clap::{Arg, ArgMatches, App, AppSettings, SubCommand};
+use doc::project_root_dir;
 
 const DEFAULT_TEMPLATE: &'static str = "README.tpl";
 
@@ -165,7 +168,13 @@ fn main() {
 }
 
 fn execute(m: &ArgMatches) {
-    let current_dir = env::current_dir().unwrap();
+    let current_dir = match project_root_dir() {
+        Some(v) => v,
+        None => {
+            println!("This doesn't look like a Rust/Cargo project");
+            return;
+        },
+    };
 
     let input = m.value_of("INPUT");
     let output = m.value_of("OUTPUT");
@@ -235,6 +244,7 @@ fn execute(m: &ArgMatches) {
         },
     };
 
+
     match dest.as_mut() {
         Some(dest) => {
             dest.write_all(doc_string.as_bytes())
@@ -247,3 +257,4 @@ fn execute(m: &ArgMatches) {
         None => println!("{}", doc_string),
     }
 }
+