Add functionality to read storeids from stdin

bin/core/imag-tag/src/main.rs

@@ -57,6 +57,7 @@ extern crate env_logger;
 
 use std::path::PathBuf;
 use std::io::Write;
+use std::io::Read;
 
 use libimagrt::runtime::Runtime;
 use libimagrt::setup::generate_runtime_setup;
@@ -82,7 +83,30 @@ fn main() {
                                     "Direct interface to the store. Use with great care!",
                                     build_ui);
 
-    let ids = rt.cli().values_of("id").unwrap().map(PathBuf::from); // enforced by clap
+    let ids : Vec<PathBuf> = rt
+        .cli()
+        .values_of("id")
+        .map(|vals| {
+            vals.map(PathBuf::from).collect()
+        }).unwrap_or_else(|| {
+            if !rt.cli().is_present("ids-from-stdin") {
+                error!("No ids");
+                ::std::process::exit(1)
+            }
+
+            let stdin = rt.stdin().unwrap_or_else(|| {
+                error!("Cannot get handle to stdin");
+                ::std::process::exit(1)
+            });
+
+            let mut buf = String::new();
+            let _ = stdin.lock().read_to_string(&mut buf).unwrap_or_else(|_| {
+                error!("Failed to read from stdin");
+                ::std::process::exit(1)
+            });
+
+            buf.lines().map(PathBuf::from).collect()
+        });
 
     rt.cli()
         .subcommand_name()

bin/core/imag-tag/src/ui.rs

@@ -30,6 +30,14 @@ pub fn build_ui<'a>(app: App<'a, 'a>) -> App<'a, 'a> {
                 .value_name("ID")
                 .help("Entry to use"))
 
+        .arg(Arg::with_name("ids-from-stdin")
+                .long("ids-from-stdin")
+                .short("I")
+                .takes_value(false)
+                .required(false)
+                .multiple(false)
+                .help("Read store ids to tag from stdin"))
+
         .subcommand(SubCommand::with_name("add")
                    .about("Add tags")
                    .version("0.1")