add silent flag (#74)

src/output/cli.rs

@@ -1,11 +1,17 @@
 use clap::Arg;
 
-pub fn output_arg<'a>() -> Arg<'a, 'a> {
-    Arg::with_name("output")
-        .long("output")
-        .short("o")
-        .help("Defines the output format")
-        .value_name("STRING")
-        .possible_values(&["plain", "json"])
-        .default_value("plain")
+pub fn output_args<'a>() -> Vec<Arg<'a, 'a>> {
+    vec![
+        Arg::with_name("output")
+            .long("output")
+            .short("o")
+            .help("Defines the output format")
+            .value_name("STRING")
+            .possible_values(&["plain", "json"])
+            .default_value("plain"),
+        Arg::with_name("silent")
+            .long("silent")
+            .short("s")
+            .help("Disables any output"),
+    ]
 }

src/output/utils.rs

@@ -41,13 +41,15 @@ pub fn run_cmd(cmd: &str) -> Result<String> {
     Ok(String::from_utf8(output.stdout)?)
 }
 
-pub fn print<T: fmt::Display + Serialize>(output_type: &str, item: T) -> Result<()> {
-    match output_type {
-        "json" => print!(
-            "{}",
-            serde_json::to_string(&item).chain_err(|| "Could not decode JSON")?
-        ),
-        "text" | _ => println!("{}", item.to_string()),
+pub fn print<T: fmt::Display + Serialize>(output_type: &str, silent: &bool, item: T) -> Result<()> {
+    if silent == &false {
+        match output_type {
+            "json" => print!(
+                "{}",
+                serde_json::to_string(&item).chain_err(|| "Could not decode JSON")?
+            ),
+            "text" | _ => println!("{}", item.to_string()),
+        }
     }
 
     Ok(())