Initial commit

src/main.rs

@@ -0,0 +1,74 @@
+use std::path::PathBuf;
+
+use clap::Parser;
+
+#[derive(Parser, Debug)]
+#[command(author, version, about, long_about = None)]
+struct Args {
+    // TODO: allow content from stdin and write to stdout
+
+    // TODO: allow disabling use of PATH for command lookups
+
+    /// Input file
+    input: PathBuf,
+
+    /// Output file
+    output: Option<PathBuf>,
+
+    /// Atomically write to output file
+    #[arg(short, long)]
+    atomic: bool,
+
+    /// Create a backup of the original file
+    #[arg(short, long)]
+    backup: bool,
+
+    /// Backup suffix
+    #[arg(long, default_value = ".bak")]
+    backup_suffix: String,
+
+    /// Make parent directories if they don't exist
+    #[arg(short = 'p', long)]
+    mkdir: bool,
+
+    /// Set mode of output file
+    #[arg(long, default_value = "0644")] // TODO: set value parser
+    mode: u32,
+
+    /// Set owner of output file (default: current user)
+    #[arg(long)]
+    owner: Option<u32>,
+
+    /// Set group of output file (default: current user's primary group)
+    #[arg(long)]
+    group: Option<u32>,
+
+    /// Show diff instead of writing to output file
+    #[arg(short, long)]
+    dry_run: bool,
+}
+
+// Allow failure modes per substitution:
+// - ignore
+// - warn
+// - error
+
+// in patterns:
+// - line number
+// - literal string
+// - regex (allow match groups)
+
+// out patterns:
+// - literal string
+// - regex with match groups
+// - environment variables
+// - file contents
+// - sockets/fifo
+// - file descriptors
+// - command output
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let args = Args::parse();
+
+    Ok(())
+}