nl: allow negative values for --line-increment and --starting-line-number

src/uu/nl/src/helper.rs

@@ -79,36 +79,18 @@ pub fn parse_options(settings: &mut crate::Settings, opts: &clap::ArgMatches) ->
             }
         }
     }
-    match opts.get_one::<String>(options::LINE_INCREMENT) {
-        None => {}
-        Some(val) => {
-            let conv: Option<u64> = val.parse().ok();
-            match conv {
-                None => {
-                    errs.push(String::from("Illegal value for -i"));
-                }
-                Some(num) => settings.line_increment = num,
-            }
-        }
-    }
     match opts.get_one::<usize>(options::NUMBER_WIDTH) {
         None => {}
         Some(num) if *num > 0 => settings.number_width = *num,
         Some(_) => errs.push(String::from(
             "Invalid line number field width: ‘0’: Numerical result out of range",
         )),
     }
-    match opts.get_one::<String>(options::STARTING_LINE_NUMBER) {
-        None => {}
-        Some(val) => {
-            let conv: Option<u64> = val.parse().ok();
-            match conv {
-                None => {
-                    errs.push(String::from("Illegal value for -v"));
-                }
-                Some(num) => settings.starting_line_number = num,
-            }
-        }
+    if let Some(num) = opts.get_one::<i64>(options::LINE_INCREMENT) {
+        settings.line_increment = *num;
+    }
+    if let Some(num) = opts.get_one::<i64>(options::STARTING_LINE_NUMBER) {
+        settings.starting_line_number = *num;
     }
     match opts.get_one::<String>(options::JOIN_BLANK_LINES) {
         None => {}

src/uu/nl/src/nl.rs

@@ -29,8 +29,8 @@ pub struct Settings {
     // The variable corresponding to -d
     section_delimiter: [char; 2],
     // The variables corresponding to the options -v, -i, -l, -w.
-    starting_line_number: u64,
-    line_increment: u64,
+    starting_line_number: i64,
+    line_increment: i64,
     join_blank_lines: u64,
     number_width: usize, // Used with String::from_char, hence usize.
     // The format of the number and the (default value for)
@@ -208,7 +208,8 @@ pub fn uu_app() -> Command {
                 .short('i')
                 .long(options::LINE_INCREMENT)
                 .help("line number increment at each line")
-                .value_name("NUMBER"),
+                .value_name("NUMBER")
+                .value_parser(clap::value_parser!(i64)),
         )
         .arg(
             Arg::new(options::JOIN_BLANK_LINES)
@@ -244,7 +245,8 @@ pub fn uu_app() -> Command {
                 .short('v')
                 .long(options::STARTING_LINE_NUMBER)
                 .help("first line number on each logical page")
-                .value_name("NUMBER"),
+                .value_name("NUMBER")
+                .value_parser(clap::value_parser!(i64)),
         )
         .arg(
             Arg::new(options::NUMBER_WIDTH)
@@ -267,7 +269,7 @@ fn nl<T: Read>(reader: &mut BufReader<T>, settings: &Settings) -> UResult<()> {
     let line_no_width_initial = line_no_width;
     // Stores the smallest integer with one more digit than line_no, so that
     // when line_no >= line_no_threshold, we need to use one more digit.
-    let mut line_no_threshold = 10u64.pow(line_no_width as u32);
+    let mut line_no_threshold = 10i64.pow(line_no_width as u32);
     let mut empty_line_count: u64 = 0;
     let fill_char = match settings.number_format {
         NumberFormat::RightZero => '0',
@@ -329,7 +331,7 @@ fn nl<T: Read>(reader: &mut BufReader<T>, settings: &Settings) -> UResult<()> {
                     if settings.renumber {
                         line_no = settings.starting_line_number;
                         line_no_width = line_no_width_initial;
-                        line_no_threshold = 10u64.pow(line_no_width as u32);
+                        line_no_threshold = 10i64.pow(line_no_width as u32);
                     }
                     &settings.header_numbering
                 }

tests/by-util/test_nl.rs

@@ -1,4 +1,4 @@
-// spell-checker:ignore ninvalid winvalid
+// spell-checker:ignore iinvalid ninvalid vinvalid winvalid
 use crate::common::util::TestScenario;
 
 #[test]
@@ -13,6 +13,7 @@ fn test_stdin_no_newline() {
         .run()
         .stdout_is("     1\tNo Newline\n");
 }
+
 #[test]
 fn test_stdin_newline() {
     new_ucmd!()
@@ -167,3 +168,68 @@ fn test_number_separator() {
             .stdout_is("     1:-:test\n");
     }
 }
+
+#[test]
+fn test_starting_line_number() {
+    for arg in ["-v10", "--starting-line-number=10"] {
+        new_ucmd!()
+            .arg(arg)
+            .pipe_in("test")
+            .succeeds()
+            .stdout_is("    10\ttest\n");
+    }
+}
+
+#[test]
+fn test_negative_starting_line_number() {
+    for arg in ["-v-10", "--starting-line-number=-10"] {
+        new_ucmd!()
+            .arg(arg)
+            .pipe_in("test")
+            .succeeds()
+            .stdout_is("   -10\ttest\n");
+    }
+}
+
+#[test]
+fn test_invalid_starting_line_number() {
+    for arg in ["-vinvalid", "--starting-line-number=invalid"] {
+        new_ucmd!()
+            .arg(arg)
+            .fails()
+            .stderr_contains("invalid value 'invalid'");
+    }
+}
+
+#[test]
+fn test_line_increment() {
+    for arg in ["-i10", "--line-increment=10"] {
+        new_ucmd!()
+            .arg(arg)
+            .pipe_in("a\nb")
+            .succeeds()
+            .stdout_is("     1\ta\n    11\tb\n");
+    }
+}
+
+#[test]
+fn test_negative_line_increment() {
+    // TODO make this test work with -10
+    for arg in ["-i-1", "--line-increment=-1"] {
+        new_ucmd!()
+            .arg(arg)
+            .pipe_in("a\nb")
+            .succeeds()
+            .stdout_is("     1\ta\n     0\tb\n");
+    }
+}
+
+#[test]
+fn test_invalid_line_increment() {
+    for arg in ["-iinvalid", "--line-increment=invalid"] {
+        new_ucmd!()
+            .arg(arg)
+            .fails()
+            .stderr_contains("invalid value 'invalid'");
+    }
+}