add hash output file option to command

.gitignore

@@ -10,4 +10,7 @@ Cargo.lock
 **/*.rs.bk
 
 # IDE
-.idea
+.idea
+
+# Build Files for paq.gif
+demo.cast

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "paq"
-version = "1.0.1"
+version = "1.1.0"
 authors = ["Gregory Langlais <general@gregorylanglais.com>"]
 edition = "2021"
 description = "Hash file or directory recursively."
@@ -30,6 +30,9 @@ blake3 = "1.3.1"
 rayon = "1.5"
 clap = { version = "4.3.0", features = ["cargo", "unstable-styles"] }
 
+[dev-dependencies]
+assert_cmd = "2.0.11"
+
 [features]
 default = ["test-cleanup"]
 test-cleanup = []

README.md

@@ -52,7 +52,7 @@ cargo install paq
 1. Find [Latest Release](https://github.com/gregl83/paq/releases) `.zip` archive for computer Operating System and Architecture.
 2. Download and extract `.zip`.
 3. Modify permissions of the extracted `paq` binary to allow execution.
-4. Move `paq` to system path.
+4. Move `paq` to a system path.
 
 ## Usage
 
@@ -64,6 +64,8 @@ Included in this repository is an [example directory](./example) containing some
 
 Run `paq [src]` to hash source file or directory. 
 
+Output hash to `.paq` file as valid JSON.
+
 For help, run `paq --help`.
 
 #### Hash Example Directory
@@ -124,9 +126,9 @@ Additionally, files or directory contents starting with dot or full stop *can* o
 ## How it Works
 
 1. Recursively get path(s) for a given source argument.
-2. Hash each path and file content if path is for a file.
-3. Sort the list of hashes to maintain consistent ordering.
-4. Compute the final hash by hashing the sorted list of hashes.
+2. Hash each path and file contents if path is to a file.
+3. Sort the list of hashes for consistent ordering.
+4. Compute the final hash by hashing the list of hashes.
 
 ## License
 

demo.sh

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+docker run --rm -ti -v .:/opt/paq -e "TERM=xterm-256color" -w /opt/paq rust /bin/bash -c "cargo install --path=. && cargo install --locked --git https://github.com/k9withabone/autocast && cargo install --locked --git https://github.com/asciinema/agg && cargo install --locked --git https://github.com/asciinema/agg && autocast --overwrite demo.yaml demo.cast && agg demo.cast paq.gif"

demo.yaml

@@ -0,0 +1,32 @@
+settings:
+  title: paq demo
+  width: 90
+  height: 24
+  prompt: "\e[92m\e[1mubuntu\e[0m:\e[94m\e[1m/home/demo\e[0m$ "
+  environment:
+    - name: TERM
+      value: "xterm-256color"
+
+instructions:
+  - !Command
+    command: paq -h
+  - !Wait 5s
+  - !Command
+    command: paq ./example
+  - !Wait 2s
+  - !Command
+    command: cd ./example
+  - !Command
+    command: paq
+  - !Wait 2s
+  - !Command
+    command: cd ..
+  - !Command
+    command: paq --ignore-hidden ./example
+  - !Wait 2s
+  - !Command
+    command: paq --ignore-hidden -o ./example
+  - !Wait 1s
+  - !Command
+    command: cat example.paq; echo
+  - !Wait 3s

src/bin.rs

@@ -5,7 +5,9 @@
 //! cargo run -- -h
 //! ```
 
-use std::path::PathBuf;
+use std::path::{PathBuf};
+use std::fs::File;
+use std::io::{Error, Write};
 use clap::{
     crate_name,
     crate_description,
@@ -22,7 +24,9 @@ use paq::hash_source;
 
 #[derive(Copy, Clone, Debug)]
 #[non_exhaustive]
-pub struct PathBufferValueParser {}
+pub struct PathBufferValueParser {
+    validate_exists: bool
+}
 
 impl TypedValueParser for PathBufferValueParser {
     type Value = PathBuf;
@@ -34,7 +38,7 @@ impl TypedValueParser for PathBufferValueParser {
         value: &std::ffi::OsStr,
     ) -> Result<Self::Value, clap::Error> {
         let path = PathBuf::from(value);
-        if !path.exists() {
+        if self.validate_exists && !path.exists() {
             let mut err = clap::Error::new(ErrorKind::InvalidValue).with_cmd(cmd);
             err.insert(
                 ContextKind::InvalidArg,
@@ -56,28 +60,63 @@ impl TypedValueParser for PathBufferValueParser {
     }
 }
 
+fn derive_output_filepath(source: &PathBuf) -> PathBuf {
+    let source_canonical = source.canonicalize().unwrap();
+    let source_filename = source_canonical.file_name().unwrap().to_str().unwrap();
+    let mut path_buffer = PathBuf::from(source_canonical.parent().unwrap());
+    path_buffer.push(format!("{}.paq", source_filename));
+    path_buffer
+}
+
+fn write_hashfile(filepath: &PathBuf, hash: &str) -> Result<(), Error> {
+    let mut file = File::create(filepath).unwrap();
+    file.write_all(format!("\"{}\"", hash).as_bytes())
+}
+
 fn main() {
+    let output_default = "<src>.paq";
     let matches = Command::new(crate_name!())
         .version(crate_version!())
         .about(crate_description!())
         .allow_external_subcommands(false)
         .arg(
             Arg::new("src")
-                .help("Source to hash (filesystem path)")
-                .value_parser(PathBufferValueParser{})
+                .value_parser(PathBufferValueParser{validate_exists: true})
                 .default_value(".")
+                .help("Source to hash (filesystem path)")
         )
         .arg(
             Arg::new("ignore-hidden")
                 .short('i')
                 .long("ignore-hidden")
-                .help("Ignore files or directories starting with dot or full stop")
                 .action(ArgAction::SetTrue)
+                .help("Ignore files or directories starting with dot or full stop")
+        )
+        .arg(
+            Arg::new("filepath")
+                .short('o')
+                .long("out")
+                .value_parser(PathBufferValueParser{validate_exists: false})
+                .require_equals(true)
+                .num_args(0..=1)
+                .default_missing_value(output_default)
+                .help(format!("Output hash (filesystem path) [default: {}]", output_default))
         )
+        .after_help("Fails if operating system denies read access to any source file.")
         .get_matches();
 
     let source = matches.get_one::<PathBuf>("src").unwrap();
     let ignore_hidden = matches.get_flag("ignore-hidden");
+    let output: Option<&PathBuf> = matches.get_one::<PathBuf>("filepath");
     let hash = hash_source(&source, ignore_hidden);
+
+    if let Some(filepath) = output {
+        let output_filepath = match filepath.to_str().unwrap() {
+            s if s == output_default => derive_output_filepath(source),
+            _ => filepath.to_path_buf()
+        };
+        write_hashfile(&output_filepath, hash.as_str()).unwrap();
+    }
+
     println!("{}", hash);
 }