Add command line parameter to specify log file (#3807)

* Add command line parameter to specify log file

I had the logs of my debug helix mixed in with the logs from the
production helix.

Add a `--log` command line argument to redirect any logs to other
files, making my debugging easier :-)

* Update completion files with `--log` argument

1 files changed, 5 insertions, 0 deletions

diff --git a/helix-term/src/args.rs b/helix-term/src/args.rs
index d16d7dfd..48c86633 100644
--- a/helix-term/src/args.rs
+++ b/helix-term/src/args.rs
@@ -14,6 +14,7 @@ pub struct Args {
     pub build_grammars: bool,
     pub split: Option<Layout>,
     pub verbosity: u64,
+    pub log_file: Option<PathBuf>,
     pub config_file: Option<PathBuf>,
     pub files: Vec<(PathBuf, Position)>,
 }
@@ -48,6 +49,10 @@ impl Args {
                     Some(path) => args.config_file = Some(path.into()),
                     None => anyhow::bail!("--config must specify a path to read"),
                 },
+                "--log" => match argv.next().as_deref() {
+                    Some(path) => args.log_file = Some(path.into()),
+                    None => anyhow::bail!("--log must specify a path to write"),
+                },
                 arg if arg.starts_with("--") => {
                     anyhow::bail!("unexpected double dash argument: {}", arg)
                 }