chore: allow using flag or env vars for both log level and file

Author: LoricAndre

README.md

@@ -649,7 +649,7 @@ or have any ideas. Pull requests are warmly welcomed.
 
 # Troubleshooting
 
-To troubleshoot what's happening, you can set the environment variable `RUST_LOG` to either `debug` or even `trace`, and set `--log-file` to a path. You can then read those logs during or after the execution to better understand what's happening. Don't hesitate to add those logs to an issue if you need help.
+To troubleshoot what's happening, you can set the environment variable `SKIM_LOG` or the flag `--log-level` to either `debug` or even `trace`, and set the environment variable `SKIM_LOG_FILE` or the flag `--log-file` to a path. You can then read those logs during or after the execution to better understand what's happening. Don't hesitate to add those logs to an issue if you need help.
 
 ## No line feed issues with nix, FreeBSD, termux
 

src/bin/main.rs

@@ -31,14 +31,17 @@ fn main() -> Result<()> {
         e.exit();
     });
     color_eyre::install()?;
-    let log_target = if let Some(ref log_file) = opts.log_file {
-        env_logger::Target::Pipe(Box::new(File::create(log_file).expect("Failed to create log file")))
-    } else {
-        env_logger::Target::Stdout
-    };
-    env_logger::builder()
-        .target(log_target)
-        .format(|buf, record| {
+    {
+        let target = if let Some(ref log_file) = opts.log_file.as_ref().or(std::env::var("SKIM_LOG_FILE").ok().as_ref())
+        {
+            env_logger::Target::Pipe(Box::new(File::create(log_file).expect("Failed to create log file")))
+        } else {
+            env_logger::Target::Stdout
+        };
+
+        let env_var = "SKIM_LOG";
+
+        let format = |buf: &mut env_logger::fmt::Formatter, record: &log::Record<'_>| {
             writeln!(
                 buf,
                 "[{} {} {} ({}:{})] [{}/{:?}] {}",
@@ -51,8 +54,23 @@ fn main() -> Result<()> {
                 std::thread::current().id(),
                 record.args()
             )
-        })
-        .init();
+        };
+
+        if let Some(level) = opts.log_level {
+            env_logger::builder()
+                .filter_level(level)
+                .parse_env(env_var)
+                .target(target)
+                .format(format)
+                .init();
+        } else {
+            env_logger::builder()
+                .parse_env(env_var)
+                .target(target)
+                .format(format)
+                .init();
+        };
+    }
     // Build the options after setting the log target
     opts = opts.build();
     trace!("Command line: {:?}", std::env::args());

src/options.rs

@@ -757,6 +757,10 @@ pub struct SkimOptions {
     #[cfg_attr(feature = "cli", arg(long, verbatim_doc_comment, help_heading = "Display", default_missing_value = "center,50%", num_args=0..))]
     pub tmux: Option<String>,
 
+    /// Set the log level
+    #[cfg_attr(feature = "cli", arg(long, help_heading = "Scripting"))]
+    pub log_level: Option<log::LevelFilter>,
+
     /// Pipe log output to a file
     #[cfg_attr(feature = "cli", arg(long, help_heading = "Scripting"))]
     pub log_file: Option<String>,
@@ -1100,6 +1104,7 @@ impl Default for SkimOptions {
             #[cfg(feature = "cli")]
             shell_bindings: false,
             flags: Default::default(),
+            log_level: Default::default(),
         }
     }
 }