TTY style disabling

either with `--color no` or when output is piped

CHANGELOG.md

@@ -1,3 +1,8 @@
+<a name="v0.7.4"></a>
+### v0.7.4 - 2021/07/01
+* `--color` option with values yes|no|auto (auto being default)
+* no tty style when `--color` is default and the output is piped
+
 <a name="v0.7.3"></a>
 ### v0.7.3 - 2021/06/30
 * fix disk not found for BTRFS filesystems - Fix #11

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "lfs"
-version = "0.7.3"
+version = "0.7.4"
 authors = ["dystroy <denys.seguret@gmail.com>"]
 edition = "2018"
 keywords = ["linux", "filesystem", "fs"]

src/args.rs

@@ -0,0 +1,54 @@
+
+use {
+    argh::FromArgs,
+    std::path::PathBuf,
+};
+
+#[derive(FromArgs)]
+/// List your filesystems.
+///
+/// All units are SI.
+///
+/// Source at https://github.com/Canop/lfs
+pub struct Args {
+    /// print the version
+    #[argh(switch, short = 'v')]
+    pub version: bool,
+
+    #[argh(option, default = "Default::default()")]
+    /// color: 'yes', 'no' or 'auto' (auto should be good in most cases)
+    pub color: BoolArg,
+
+    /// whether to show all mount points
+    #[argh(switch, short = 'a')]
+    pub all: bool,
+
+    /// output as JSON
+    #[argh(switch, short = 'j')]
+    pub json: bool,
+
+    #[argh(positional)]
+    /// if a path is provided, only the device holding this path will be shown
+    pub path: Option<PathBuf>,
+}
+
+/// An optional boolean for use in Argh
+#[derive(Debug, Clone, Copy, Default)]
+pub struct BoolArg(Option<bool>);
+
+impl BoolArg {
+    pub fn value(self) -> Option<bool> {
+        self.0
+    }
+}
+
+impl argh::FromArgValue for BoolArg {
+    fn from_arg_value(value: &str) -> Result<Self, String> {
+        match value.to_lowercase().as_ref() {
+            "auto" => Ok(BoolArg(None)),
+            "yes" => Ok(BoolArg(Some(true))),
+            "no" => Ok(BoolArg(Some(false))),
+            _ => Err(format!("Illegal value: {:?}", value)),
+        }
+    }
+}

src/fmt_mount.rs

@@ -25,7 +25,7 @@ ${mount-points
 |-:
 "#;
 
-pub fn print(mounts: &[Mount]) -> Result<()> {
+pub fn print(mounts: &[Mount], color: bool) -> Result<()> {
     let mut expander = OwningTemplateExpander::new();
     expander.set_default("");
     for mount in mounts {
@@ -51,14 +51,22 @@ pub fn print(mounts: &[Mount]) -> Result<()> {
     let (width, _) = terminal_size();
     let template = TextTemplate::from(MD);
     let text = expander.expand(&template);
-    let skin = MadSkin {
+    let skin = if color {
+        make_colored_skin()
+    } else {
+        MadSkin::no_style()
+    };
+    let fmt_text = FmtText::from_text(&skin, text, Some(width as usize));
+    print!("{}", fmt_text);
+    Ok(())
+}
+
+fn make_colored_skin() -> MadSkin {
+    MadSkin {
         bold: CompoundStyle::with_fg(AnsiValue(SIZE_COLOR)), // size
         inline_code: CompoundStyle::with_fg(AnsiValue(USED_COLOR)), // use%
         strikeout: CompoundStyle::with_fgbg(AnsiValue(USED_COLOR), AnsiValue(AVAI_COLOR)), // use bar
         italic: CompoundStyle::with_fg(AnsiValue(AVAI_COLOR)), // available
         ..Default::default()
-    };
-    let fmt_text = FmtText::from_text(&skin, text, Some(width as usize));
-    print!("{}", fmt_text);
-    Ok(())
+    }
 }

src/main.rs

@@ -1,35 +1,17 @@
+mod args;
 mod fmt_mount;
 mod json;
 
 use {
-    argh::FromArgs,
-    std::{cmp::Reverse, fs, os::unix::fs::MetadataExt, path::PathBuf},
+    crate::args::*,
+    crossterm::tty::IsTty,
+    std::{
+        cmp::Reverse,
+        fs,
+        os::unix::fs::MetadataExt,
+    },
 };
 
-#[derive(FromArgs)]
-/// List your filesystems.
-///
-/// All units are SI.
-///
-/// Source at https://github.com/Canop/lfs
-struct Args {
-    /// print the version
-    #[argh(switch, short = 'v')]
-    version: bool,
-
-    /// whether to show all mount points
-    #[argh(switch, short = 'a')]
-    all: bool,
-
-    /// output as JSON
-    #[argh(switch, short = 'j')]
-    json: bool,
-
-    #[argh(positional)]
-    /// if a path is provided, only the device holding this path will be shown
-    pub path: Option<PathBuf>,
-}
-
 fn main() -> lfs_core::Result<()> {
     let args: Args = argh::from_env();
     if args.version {
@@ -59,6 +41,8 @@ fn main() -> lfs_core::Result<()> {
         Ok(())
     } else {
         mounts.sort_by_key(|m| Reverse(m.size()));
-        fmt_mount::print(&mounts)
+        let color = args.color.value()
+            .unwrap_or_else(|| std::io::stdout().is_tty());
+        fmt_mount::print(&mounts, color)
     }
 }