numfmt: implement "--to-unit" & "--from-unit"

src/uu/numfmt/src/format.rs

@@ -1,6 +1,6 @@
 use uucore::display::Quotable;
 
-use crate::options::{NumfmtOptions, RoundMethod};
+use crate::options::{NumfmtOptions, RoundMethod, TransformOptions};
 use crate::units::{DisplayableSuffix, RawSuffix, Result, Suffix, Unit, IEC_BASES, SI_BASES};
 
 /// Iterate over a line's fields, where each field is a contiguous sequence of
@@ -127,10 +127,11 @@ fn remove_suffix(i: f64, s: Option<Suffix>, u: &Unit) -> Result<f64> {
     }
 }
 
-fn transform_from(s: &str, opts: &Unit) -> Result<f64> {
+fn transform_from(s: &str, opts: &TransformOptions) -> Result<f64> {
     let (i, suffix) = parse_suffix(s)?;
+    let i = i * (opts.from_unit as f64);
 
-    remove_suffix(i, suffix, opts).map(|n| if n < 0.0 { -n.abs().ceil() } else { n.ceil() })
+    remove_suffix(i, suffix, &opts.from).map(|n| if n < 0.0 { -n.abs().ceil() } else { n.ceil() })
 }
 
 /// Divide numerator by denominator, with rounding.
@@ -206,8 +207,9 @@ fn consider_suffix(n: f64, u: &Unit, round_method: RoundMethod) -> Result<(f64,
     }
 }
 
-fn transform_to(s: f64, opts: &Unit, round_method: RoundMethod) -> Result<String> {
-    let (i2, s) = consider_suffix(s, opts, round_method)?;
+fn transform_to(s: f64, opts: &TransformOptions, round_method: RoundMethod) -> Result<String> {
+    let (i2, s) = consider_suffix(s, &opts.to, round_method)?;
+    let i2 = i2 / (opts.to_unit as f64);
     Ok(match s {
         None => format!("{}", i2),
         Some(s) if i2.abs() < 10.0 => format!("{:.1}{}", i2, DisplayableSuffix(s)),
@@ -227,8 +229,8 @@ fn format_string(
     };
 
     let number = transform_to(
-        transform_from(source_without_suffix, &options.transform.from)?,
-        &options.transform.to,
+        transform_from(source_without_suffix, &options.transform)?,
+        &options.transform,
         options.round,
     )?;
 

src/uu/numfmt/src/numfmt.rs

@@ -13,6 +13,7 @@ use crate::options::*;
 use crate::units::{Result, Unit};
 use clap::{crate_version, Arg, ArgMatches, Command};
 use std::io::{BufRead, Write};
+use units::{IEC_BASES, SI_BASES};
 use uucore::display::Quotable;
 use uucore::error::UResult;
 use uucore::format_usage;
@@ -96,11 +97,66 @@ fn parse_unit(s: &str) -> Result<Unit> {
     }
 }
 
+// Parses a unit size. Suffixes are turned into their integer representations. For example, 'K'
+// will return `Ok(1000)`, and '2K' will return `Ok(2000)`.
+fn parse_unit_size(s: &str) -> Result<usize> {
+    let number: String = s.chars().take_while(char::is_ascii_digit).collect();
+    let suffix = &s[number.len()..];
+
+    if number.is_empty() || "0".repeat(number.len()) != number {
+        if let Some(multiplier) = parse_unit_size_suffix(suffix) {
+            if number.is_empty() {
+                return Ok(multiplier);
+            }
+
+            if let Ok(n) = number.parse::<usize>() {
+                return Ok(n * multiplier);
+            }
+        }
+    }
+
+    Err(format!("invalid unit size: {}", s.quote()))
+}
+
+// Parses a suffix of a unit size and returns the corresponding multiplier. For example,
+// the suffix 'K' will return `Some(1000)`, and 'Ki' will return `Some(1024)`.
+//
+// If the suffix is empty, `Some(1)` is returned.
+//
+// If the suffix is unknown, `None` is returned.
+fn parse_unit_size_suffix(s: &str) -> Option<usize> {
+    if s.is_empty() {
+        return Some(1);
+    }
+
+    let suffix = s.chars().next().unwrap();
+
+    if let Some(i) = ['K', 'M', 'G', 'T', 'P', 'E']
+        .iter()
+        .position(|&ch| ch == suffix)
+    {
+        return match s.len() {
+            1 => Some(SI_BASES[i + 1] as usize),
+            2 if s.ends_with('i') => Some(IEC_BASES[i + 1] as usize),
+            _ => None,
+        };
+    }
+
+    None
+}
+
 fn parse_options(args: &ArgMatches) -> Result<NumfmtOptions> {
     let from = parse_unit(args.value_of(options::FROM).unwrap())?;
     let to = parse_unit(args.value_of(options::TO).unwrap())?;
+    let from_unit = parse_unit_size(args.value_of(options::FROM_UNIT).unwrap())?;
+    let to_unit = parse_unit_size(args.value_of(options::TO_UNIT).unwrap())?;
 
-    let transform = TransformOptions { from, to };
+    let transform = TransformOptions {
+        from,
+        from_unit,
+        to,
+        to_unit,
+    };
 
     let padding = match args.value_of(options::PADDING) {
         Some(s) => s
@@ -222,6 +278,13 @@ pub fn uu_app<'a>() -> Command<'a> {
                 .value_name("UNIT")
                 .default_value(options::FROM_DEFAULT),
         )
+        .arg(
+            Arg::new(options::FROM_UNIT)
+                .long(options::FROM_UNIT)
+                .help("specify the input unit size")
+                .value_name("N")
+                .default_value(options::FROM_UNIT_DEFAULT),
+        )
         .arg(
             Arg::new(options::TO)
                 .long(options::TO)
@@ -229,6 +292,13 @@ pub fn uu_app<'a>() -> Command<'a> {
                 .value_name("UNIT")
                 .default_value(options::TO_DEFAULT),
         )
+        .arg(
+            Arg::new(options::TO_UNIT)
+                .long(options::TO_UNIT)
+                .help("the output unit size")
+                .value_name("N")
+                .default_value(options::TO_UNIT_DEFAULT),
+        )
         .arg(
             Arg::new(options::PADDING)
                 .long(options::PADDING)
@@ -280,7 +350,10 @@ pub fn uu_app<'a>() -> Command<'a> {
 
 #[cfg(test)]
 mod tests {
-    use super::{handle_buffer, NumfmtOptions, Range, RoundMethod, TransformOptions, Unit};
+    use super::{
+        handle_buffer, parse_unit_size, parse_unit_size_suffix, NumfmtOptions, Range, RoundMethod,
+        TransformOptions, Unit,
+    };
     use std::io::{BufReader, Error, ErrorKind, Read};
     struct MockBuffer {}
 
@@ -294,7 +367,9 @@ mod tests {
         NumfmtOptions {
             transform: TransformOptions {
                 from: Unit::None,
+                from_unit: 1,
                 to: Unit::None,
+                to_unit: 1,
             },
             padding: 10,
             header: 1,
@@ -338,4 +413,35 @@ mod tests {
         let result = handle_buffer(BufReader::new(&input_value[..]), &get_valid_options());
         assert!(result.is_ok(), "did not return Ok for valid input");
     }
+
+    #[test]
+    fn test_parse_unit_size() {
+        assert_eq!(1, parse_unit_size("1").unwrap());
+        assert_eq!(1, parse_unit_size("01").unwrap());
+        assert!(parse_unit_size("1.1").is_err());
+        assert!(parse_unit_size("0").is_err());
+        assert!(parse_unit_size("-1").is_err());
+        assert!(parse_unit_size("A").is_err());
+        assert!(parse_unit_size("18446744073709551616").is_err());
+    }
+
+    #[test]
+    fn test_parse_unit_size_with_suffix() {
+        assert_eq!(1000, parse_unit_size("K").unwrap());
+        assert_eq!(1024, parse_unit_size("Ki").unwrap());
+        assert_eq!(2000, parse_unit_size("2K").unwrap());
+        assert_eq!(2048, parse_unit_size("2Ki").unwrap());
+        assert!(parse_unit_size("0K").is_err());
+    }
+
+    #[test]
+    fn test_parse_unit_size_suffix() {
+        assert_eq!(1, parse_unit_size_suffix("").unwrap());
+        assert_eq!(1000, parse_unit_size_suffix("K").unwrap());
+        assert_eq!(1024, parse_unit_size_suffix("Ki").unwrap());
+        assert_eq!(1000 * 1000, parse_unit_size_suffix("M").unwrap());
+        assert_eq!(1024 * 1024, parse_unit_size_suffix("Mi").unwrap());
+        assert!(parse_unit_size_suffix("Kii").is_none());
+        assert!(parse_unit_size_suffix("A").is_none());
+    }
 }

src/uu/numfmt/src/options.rs

@@ -6,6 +6,8 @@ pub const FIELD: &str = "field";
 pub const FIELD_DEFAULT: &str = "1";
 pub const FROM: &str = "from";
 pub const FROM_DEFAULT: &str = "none";
+pub const FROM_UNIT: &str = "from-unit";
+pub const FROM_UNIT_DEFAULT: &str = "1";
 pub const HEADER: &str = "header";
 pub const HEADER_DEFAULT: &str = "1";
 pub const NUMBER: &str = "NUMBER";
@@ -14,10 +16,14 @@ pub const ROUND: &str = "round";
 pub const SUFFIX: &str = "suffix";
 pub const TO: &str = "to";
 pub const TO_DEFAULT: &str = "none";
+pub const TO_UNIT: &str = "to-unit";
+pub const TO_UNIT_DEFAULT: &str = "1";
 
 pub struct TransformOptions {
     pub from: Unit,
+    pub from_unit: usize,
     pub to: Unit,
+    pub to_unit: usize,
 }
 
 pub struct NumfmtOptions {

tests/by-util/test_numfmt.rs

@@ -607,3 +607,35 @@ fn test_invalid_padding_value() {
             .stderr_contains(format!("invalid padding value '{}'", padding_value));
     }
 }
+
+#[test]
+fn test_from_unit() {
+    new_ucmd!()
+        .args(&["--from-unit=512", "4"])
+        .succeeds()
+        .stdout_is("2048\n");
+}
+
+#[test]
+fn test_to_unit() {
+    new_ucmd!()
+        .args(&["--to-unit=512", "2048"])
+        .succeeds()
+        .stdout_is("4\n");
+}
+
+#[test]
+fn test_invalid_unit_size() {
+    let commands = vec!["from", "to"];
+    let invalid_sizes = vec!["A", "0", "18446744073709551616"];
+
+    for command in commands {
+        for invalid_size in &invalid_sizes {
+            new_ucmd!()
+                .arg(format!("--{}-unit={}", command, invalid_size))
+                .fails()
+                .code_is(1)
+                .stderr_contains(format!("invalid unit size: '{}'", invalid_size));
+        }
+    }
+}