Add implementation for validators

libimagutil/src/cli_validators.rs

@@ -0,0 +1,26 @@
+//! Functions to be used for clap::Arg::validator()
+//! to validate arguments
+
+use std::path::PathBuf;
+use boolinator::Boolinator;
+
+pub fn is_file(s: String) -> Result<(), String> {
+    PathBuf::from(s.clone()).is_file().as_result((), format!("Not a File: {}", s))
+}
+
+pub fn is_directory(s: String) -> Result<(), String> {
+    PathBuf::from(s.clone()).is_dir().as_result((), format!("Not a Directory: {}", s))
+}
+
+pub fn is_integer(s: String) -> Result<(), String> {
+    use std::str::FromStr;
+
+    let i : Result<i64, _> = FromStr::from_str(&s);
+    i.map(|_| ()).map_err(|_| format!("Not an integer: {}", s))
+}
+
+pub fn is_url(s: String) -> Result<(), String> {
+    use url::Url;
+    Url::parse(&s).map(|_| ()).map_err(|_| format!("Not a URL: {}", s))
+}
+