replace `--no-style` with `--color` taking `yes`, `no` or `auto`

When in `auto` (which is default) broot detects whether the output
is piped and removes styles and colors in that case.

Fix #347

5 files changed, 33 insertions, 5 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3ad2e4a..e64d278 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+### next
+- fix style characters being written in `--no-style` mode - Fix #346
+- replace `--no-style` with `--color` taking `yes`, `no` or `auto`, with detection of output being piped in `auto` mode (default). `--no-style` is still usable but it's not documented anymore - Fix #347
+
 <a name="v1.2.4"></a>
 ### v1.2.4 - 2021-02-14
 - :line_down_no_cycle and :line_up_nocycle. They may be mapped instead of :line_up and :line_down when you don't want to cycle (ie arrive on top when you go down past the end of the tree/list) - Fix #344
diff --git a/src/clap.rs b/src/clap.rs
index d161747..765a8bf 100644
--- a/src/clap.rs
+++ b/src/clap.rs
@@ -159,6 +159,14 @@ pub fn clap_app() -> clap::App<'static, 'static> {
                 .help("Semicolon separated commands to execute"),
         )
         .arg(
+            clap::Arg::with_name("color")
+                .long("color")
+                .takes_value(true)
+                .possible_values(&["yes", "no", "auto"])
+                .default_value("auto")
+                .help("Whether to have styles and colors (auto is default and usually OK)"),
+        )
+        .arg(
             clap::Arg::with_name("conf")
                 .long("conf")
                 .takes_value(true)
@@ -184,6 +192,7 @@ pub fn clap_app() -> clap::App<'static, 'static> {
         )
         .arg(
             clap::Arg::with_name("no-style")
+                .hidden(true) // we're deprecating this in favor of --color
                 .long("no-style")
                 .help("Whether to remove all style and colors from exported tree"),
         )
diff --git a/src/cli.rs b/src/cli.rs
index a250dbe..8bed34d 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -120,6 +120,21 @@ fn get_root_path(cli_args: &ArgMatches<'_>) -> Result<PathBuf, ProgramError> {
     Ok(canonicalize_root(&root)?)
 }
 
+fn is_output_piped() -> bool {
+    unsafe { libc::isatty(libc::STDOUT_FILENO) == 0 }
+}
+
+fn is_no_style(cli_matches: &ArgMatches) -> bool {
+    if cli_matches.is_present("no-style") {
+        return true;
+    }
+    match cli_matches.value_of("color") {
+        Some("yes") => false,
+        Some("no") => true,
+        _  => is_output_piped(),
+    }
+}
+
 /// run the application, and maybe return a launchable
 /// which must be run after broot
 pub fn run() -> Result<Option<Launchable>, ProgramError> {
@@ -189,7 +204,7 @@ pub fn run() -> Result<Option<Launchable>, ProgramError> {
     let file_export_path = cli_matches.value_of("file-export-path").map(str::to_string);
     let cmd_export_path = cli_matches.value_of("cmd-export-path").map(str::to_string);
     let commands = cli_matches.value_of("commands").map(str::to_string);
-    let no_style = cli_matches.is_present("no-style");
+    let no_style = is_no_style(&cli_matches);
     let height = cli_matches.value_of("height").and_then(|s| s.parse().ok());
 
     let root = get_root_path(&cli_matches)?;
diff --git a/website/docs/export.md b/website/docs/export.md
index 64d5a83..8f396ce 100644
--- a/website/docs/export.md
+++ b/website/docs/export.md
@@ -10,9 +10,9 @@ Example with a filter:
 
 ![exported styled tree](img/20190321-cmd-pt-styled.png)
 
-Example without style or color, thanks to `--no-style`:
+Example without style or color, thanks to `--color no`:
 
-![exported unstyled tree](img/20190321-cmd-pt-unstyled.png)
+![exported unstyled tree](img/20210222-cmd-pt-unstyled.png)
 
 This is also how would look the tree directly exported into a file.
 
@@ -24,13 +24,13 @@ You don't have to enter broot, you may also directly get the tree by using the [
 
 For example
 
-    broot --cmd ":pt" --no-style > my_file.txt
+    br --cmd ":pt" > my_file.txt
 
 will export the local tree to the `my_file.txt` file.
 
 Or
 
-    broot --no-style > tree.txt
+    br > tree.txt
 
 in which case you'll manually do `:pt` when in broot but after having had the opportunity to navigate, filter and change toggles as desired.
 
diff --git a/website/docs/img/20210222-cmd-pt-unstyled.png b/website/docs/img/20210222-cmd-pt-unstyled.png
new file mode 100644
index 0000000..761c06a
--- /dev/null
+++ b/website/docs/img/20210222-cmd-pt-unstyled.png