Enable the use of response files

The usual syntax of "@filename" is implemented to read arguments from "filename".

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "a2ltool"
-version = "2.0.1"
+version = "2.0.2"
 authors = ["Daniel Thaler <daniel@dthaler.de>"]
 edition = "2021"
 license = "MIT OR Apache-2.0"
@@ -17,6 +17,7 @@ cpp_demangle = "0.4.3"
 regex = "1"
 indexmap = "2.2.0"
 fxhash = "0.2.1"
+argfile = { version ="0.2.0", features=["response"]}
 
 [profile.release]
 panic = "abort"

README.md

@@ -17,23 +17,48 @@ A tool to edit, merge and update a2l files
 
 `a2ltool file1.a2l --merge file2.a2l --output merged.a2l`
 
+### Merge multiple a2l files
+
+`a2ltool file1.a2l --merge file2.a2l --merge file3.a2l --merge file4.a2l --output merged.a2l`
+
+### Merge all included files into the main file
+
+`a2ltool file1.a2l --merge-includes --output flat.a2l`
+
 ### Update the addresses in an a2l file
 
 `a2ltool input.a2l --elffile input.elf --update --output updated.a2l`
 
-### Create a new a2lfile and add a characteristic from an elf file to it
+### Update the addresses in an a2l file, while keeping invalid elements
+
+`a2ltool input.a2l --elffile input.elf --update-preserve --output updated.a2l`
+
+### Create a new a2l file and add a characteristic from an elf file to it
 
 `a2ltool --create --elffile input.elf --characteristic my_var --output newfile.a2l`
 
+### Create a new a2l file and add multiple measurements from an elf file to it using a regular expression
+
+`a2ltool --create --elffile input.elf --measurement-regex ".*name_pattern\d\d+*" --output newfile.a2l`
+
+### Create a new a2l file and add multiple measurements from an elf file to it using an address range
+
+`a2ltool --create --elffile input.elf --measurement-range 0x1000 0x3000 --output newfile.a2l`
+
+### Change the version of an a2l file, while deleting any incompatible elements
+
+`a2ltool input.a2l --a2lversion 1.5.1 --output downgraded.a2l`
+
+### Use response files containing command arguments
+
+Assume that the file `a2ltool.rsp` exists and contains valid arguments for `a2ltool`.
+
+`a2ltool @a2ltool.rsp`
+
 ## About a2l Files
 
 A2l files describe measurement variables and tunable parameters of an embedded device (typically: an automotive ECU).
 
 The consumer of the a2l file typically allows online calibraction over a protocol such as XCP and/or offline tuning by generating flashable parameter sets. There are several commercial tools for this purpose.
 
 The a2l file format is specified by ASAM and is formally called ASAM MCD-2 MC.
-
-## Project Status
-
-With a2ltool version 1.0 all initially planned features were fully implemented.
-Further improvements have been made as needed since then - see the changelog.

src/main.rs

@@ -1,3 +1,4 @@
+use argfile;
 use clap::{builder::ValueParser, parser::ValuesRef, Arg, ArgGroup, ArgMatches, Command};
 
 use a2lfile::{A2lError, A2lFile, A2lObject};
@@ -541,6 +542,12 @@ fn load_or_create_a2l(
 // set up the entire command line handling.
 // fortunately clap makes this painless
 fn get_args() -> ArgMatches {
+    let args = std::env::args_os();
+    let args = argfile::expand_args_from(args, argfile::parse_response, argfile::PREFIX)
+        .unwrap_or_else(|err| {
+            println!("invalid response file: {err}: {}", err.kind());
+            std::env::args_os().into_iter().collect()
+        });
     Command::new("a2ltool")
     .version(env!("CARGO_PKG_VERSION"))
     .about("Reads, writes and modifies A2L files")
@@ -781,7 +788,7 @@ fn get_args() -> ArgMatches {
             .multiple(true)
     )
     .next_line_help(false)
-    .get_matches()
+    .get_matches_from(args)
 }
 
 fn range_args_to_ranges(args: Option<ValuesRef<u64>>) -> Vec<(u64, u64)> {