'first' gets first row if no amount desired given.

src/commands/first.rs

@@ -7,7 +7,7 @@ pub struct First;
 
 #[derive(Deserialize)]
 pub struct FirstArgs {
-    amount: Tagged<u64>,
+    rows: Option<Tagged<u64>>,
 }
 
 impl WholeStreamCommand for First {
@@ -16,7 +16,7 @@ impl WholeStreamCommand for First {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("first").required("amount", SyntaxShape::Int)
+        Signature::build("first").optional("rows", SyntaxShape::Int)
     }
 
     fn usage(&self) -> &str {
@@ -33,8 +33,15 @@ impl WholeStreamCommand for First {
 }
 
 fn first(
-    FirstArgs { amount }: FirstArgs,
+    FirstArgs { rows }: FirstArgs,
     context: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
-    Ok(OutputStream::from_input(context.input.values.take(*amount)))
+
+    let rows_desired = if let Some(quantity) = rows {
+        *quantity
+    } else {
+        1
+    };
+
+    Ok(OutputStream::from_input(context.input.values.take(rows_desired)))
 }