help and version flags

1 files changed, 58 insertions, 0 deletions

diff --git a/src/flags.rs b/src/flags.rs
new file mode 100644
index 0000000..91acf3a
--- /dev/null
+++ b/src/flags.rs
@@ -0,0 +1,58 @@
+pub struct Flags {
+  pub help: bool,
+  pub version: bool,
+  pub dont_persist: bool,
+  pub arg_count: usize
+}
+
+pub fn parse(args: &[String]) -> Flags {
+  let mut flags = Flags { 
+    help: false, 
+    version: false,
+    dont_persist: false, 
+    arg_count: 0 
+  };
+  for arg in args {
+    if !is_arg(&arg) { break; }
+    flags.arg_count += 1;
+    if arg.starts_with("--") {
+      let flag = &arg[2..];
+      check_flag(&flag, &mut flags);
+    } else {
+      let flag = &arg[1..];
+      for char in flag.chars() {
+        check_flag(&char.to_string(), &mut flags);
+      }
+    }
+  }
+  flags
+}
+
+fn is_arg(arg: &str) -> bool {
+  return arg.starts_with("-");
+}
+
+const HELP_FLAG:              &str = "help h";
+const VERSION_FLAG:           &str = "version v";
+const DONT_PERSIST:           &str = "d";
+
+fn check_flag(arg: &str, flags: &mut Flags) {
+  if has_flag_set(&arg, HELP_FLAG) {
+    flags.help = true
+  }
+  if has_flag_set(&arg, VERSION_FLAG) {
+    flags.version = true
+  }
+  if has_flag_set(&arg, DONT_PERSIST) {
+    flags.dont_persist = true
+  }
+}
+
+fn has_flag_set(arg: &str, check: &str) -> bool {
+  for check_arg in check.split(" ") {
+    if check_arg == arg {
+      return true
+    }
+  }
+  return false
+}
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