wrote readme and added (un)install scripts

README.md

@@ -2,14 +2,75 @@
 
 Makefile generator for C projects.
 
-`mgen` automatically generates build rules for all source files (extension `.c`)
-it finds in a recursive search of the directory in which it is run. It reads the
-varibles from your existing Makefile and uses them when generating the new
-targets.
+## Overview
+
+`mgen` automatically generates build rules for all source files (extension `.c`)
+it finds in a recursive search of the directory in which it is run. It places
+the rules in your existing makefile, meaning you can easily change build options
+and even write your own rules based on those generated. 
+
+`mgen` will place the generated rules between the strings "`#=mgen_start=#`" and
+"`#=mgen_end=#`" in your makefile. If these lines are not present, it will add
+them to the end of the file and place the rules there. Anything not between
+these lines will not be touched by `mgen`. 
+
+`mgen` utilizes certain common make variables when generating the build rules.
+These are:
 
-The following varibles are supported:
  - CC      -> C compiler
  - CFLAGS  -> compilation flags
  - LDLIBS  -> linker libraries
  - LDFLAGS -> linker flags
  - TARGET  -> name of final executable/library
+
+It is therefore recommended that you set these at the beginning of your
+makefile, unless you want to use the `make` defaults.
+
+`mgen`'s rules will place all compiled files in the `BUILD_DIR` specified on the
+command line (see *Usage* section of this README). Objects will be placed in the
+directory `BUILD_DIR/obj/`, and the `TARGET` will be placed at
+`BUILD_DIR/$(TARGET)`.
+
+## Usage
+
+```
+$ mgen --help
+Usage: mgen [OPTIONS] [BUILD_DIR]                                                                                                                                                                                                             
+                                                                                                                                                                                                                                              
+Arguments:                                                                                                                                                                                                                                    
+  [BUILD_DIR]  Directory to place build files [default: ./build]                                                                                                                                                                              
+                                                                                                                                                                                                                                              
+Options:                                                                                                                                                                                                                                      
+  -p, --pretty               Replace default make output with nice build messages                                                                                                                                                             
+  -m, --makefile <MAKEFILE>  Path to makefile [default: ./Makefile]                                                                                                                                                                           
+  -h, --help                 Print help                                                                                                                                                                                                       
+```
+
+Starting from a "blank slate," i.e. you have no build system configured in your
+project, simply run `mgen` in the root directory and then run `make`. It's as
+easy as that.
+
+If you already have a makefile in use, remove any rules to build the target or
+object files (that what `mgen` is for). You can keep any other, more complex
+rules that depend on these things, though. Then, run `mgen` and `make` and you
+are good to go.
+
+## Build Instructions
+
+Build: `cargo build --release`
+Install (must build first) (needs root): `sh install.sh`
+Uninstall (needs root): `sh uninstall.sh`
+
+## Todo
+
+- Add functionality to generate rules to build a library, as opposed to an
+  executable.
+- Add options to generate convenient rules like `clean` to remove all build
+  files, `run` to execute the target, etc.
+- Don't create new makefile if no `.c` files are found.
+- Add exclude directory(ies) from search
+- Eventually: write man page.
+- Maybe: allow build directory to be specified within the Makefile ?
+- Maybe: figure out a way to only have the user run `mgen` once, then the
+  makefile itself will call it again if it needs to be regenerated due to a
+  change in project structure ?

install.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+cp ./target/release/mgen /usr/bin/mgen

src/main.rs

@@ -102,6 +102,14 @@ fn main() {
         fs::File::create(&args.makefile).unwrap();
     }
 
+    if !Path::new(&args.build_dir).exists() {
+        fs::create_dir(&args.build_dir).unwrap();
+    }
+
+    if !obj_dir.exists() {
+        fs::create_dir(obj_dir).unwrap();
+    }
+
     let mut makefile_handle = fs::OpenOptions::new()
         .read(true)
         .open(args.makefile.clone()).unwrap();
@@ -117,6 +125,7 @@ fn main() {
 
     build_rules.push_str("\n");
 
+    // Target linking rule
     let target_path = build_dir.join(Path::new("$(TARGET)"));
     let target_path = target_path.to_str().unwrap();
 
@@ -140,7 +149,9 @@ fn main() {
     if pretty {
         build_rules.push_str(&format!("\t@printf 'done\\n'\n"));
     }
+    // ----------
 
+    // Rules for each object file
     for file in project_files.iter() {
         let mut build_rule = String::new();
 
@@ -168,6 +179,7 @@ fn main() {
 
         build_rules.push_str(&build_rule);
     }
+    // ----------
 
     build_rules.push_str(&end_key);
 

uninstall.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+rm /usr/bin/mgen