Spawn `pass` in order to support GnuPG 2 and Pinentry

Previously, Passextract didn't work with GnuPG 2 because I was
immediately collecting the output of `pass`.

With GnuPG 1.4, the password prompt was like a conventional `read`-style
password prompt. However, in GnuPG 2, the prompt is replaced with
Pinentry. Pinentry interferes with capturing the output from Pass, such
that Passextract exits immediately, without even prompting for a
password.

Instead of using `Command.output`, use `Command.spawn`. This allows
GnuPG to work correctly and display a Pinentry prompt. We can then
capture the standard output from the child process and parse it for the
Passextract interface.

1 files changed, 25 insertions, 6 deletions

diff --git a/src/main.rs b/src/main.rs
index 47095b8..7701dd3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -63,15 +63,34 @@ fn parse_options(filename: &str) -> Vec<String> {
             push_option(&mut options, line.to_owned());
         }
     } else {
-        let file = Command::new("pass")
+        let mut child = Command::new("pass")
             .arg("show")
             .arg(filename)
-            .output()
-            .expect("Error executing `pass`")
-            .stdout;
+            .stdout(std::process::Stdio::piped())
+            .spawn()
+            .expect("Error executing `pass`");
 
-        for line in String::from_utf8_lossy(&file).lines() {
-            push_option(&mut options, line.to_owned());
+        child.wait().expect("Error waiting for `pass`");
+
+        let stdout = child.stdout.take().unwrap();
+
+        // let file = stdout;
+        // let stdout = child.stdout.unwrap();
+        let file = io::BufReader::new(stdout);
+
+        // let mut line = String::new();
+
+        // loop {
+        //     let n_bytes = file.read_line(&mut line).unwrap();
+        //     if n_bytes == 0 {
+        //         break;
+        //     }
+        //
+        //     push_option(&mut options, line.to_owned());
+        // }
+
+        for line in file.lines() {
+            push_option(&mut options, line.unwrap());
         }
     }