Feature-gated `-exec/{}` as "exec". Added feature `mode-flags` to enable/disable collect-noallocate collect-preallocate memfile-total-jemalloc.png features that involve runtime flags.

Fortune for collect's current commit: Future blessing − 末吉

Cargo.toml

@@ -18,10 +18,13 @@ license = "GPL-3.0-or-later"
 #
 # # Logging
 # Tracing can be disabled at compile-time for higher performance by disabling the `logging` feature (see above, but remove `,logging` from the features.)
-default = ["mode-memfile", "logging"]
+default = ["mode-memfile", "mode-flags", "logging"]
 
 ## --- Modes --- ##
 
+# Enable all flag options
+mode-flags = ["exec"]
+
 # Mode: default
 # Use physical-memory backed kernel file-descriptors. (see feature `memfile`.)
 mode-memfile = ["memfile"] #, "tracing/release_max_level_warn"]
@@ -32,6 +35,9 @@ mode-buffered = ["jemalloc", "bytes"]
 
 ## --- Individual features --- ##
 
+# Enable `-exec/{}` flag options
+exec = []
+
 # Use an in-memory file for storage instead of a byte-buffer.
 #
 # This can draastically improve performance as it allows for the use of `splice()` and `send_file()` syscalls instead of many `read()` and `write()` ones.

src/main.rs

@@ -87,6 +87,7 @@ use sys::{
     tell_file,
 };
 
+#[cfg(feature="exec")] 
 mod exec;
 
 mod buffers;
@@ -600,7 +601,9 @@ fn main() -> errors::DispersedResult<()> {
     if_trace!(debug!("initialised"));
 
     //TODO: How to cleanly feature-gate `args`?
-    let opt = {
+    
+    let opt = { cfg_if!{
+	if #[cfg(feature="exec")] {
 	    #[cfg(feature="logging")]
 	    let _span = debug_span!("args");
 	    #[cfg(feature="logging")]
@@ -608,7 +611,10 @@ fn main() -> errors::DispersedResult<()> {
 	    let parsed = parse_args()?;
 	    if_trace!(debug!("Parsed arguments: {parsed:?}"));
 	    parsed
-    };
+	} else {
+	    ()
+	}
+    } };
 
     //TODO: maybe look into fd SEALing? Maybe we can prevent a consumer process from reading from stdout until we've finished the transfer. The name SEAL sounds like it might have something to do with that?
     let execfile;
@@ -621,7 +627,10 @@ fn main() -> errors::DispersedResult<()> {
 		.wrap_err("Operation failed").with_note(|| "Strategy was `buffered`")?;
 	}
     }
-    // Transfer complete, run exec.
+    // Transfer complete, run exec if enabled
+    
+    let rc = { cfg_if! {
+	if #[cfg(feature="exec")] {
 	    let rc = if let Some(file) = execfile.get_exec_file() {
 		exec::spawn_from_sync(&file, opt).into_iter().try_fold(0i32, |opt, res| res.map(|x| opt | x.unwrap_or(0)))
 	    } else {
@@ -632,6 +641,11 @@ fn main() -> errors::DispersedResult<()> {
 		0 => trace!("-exec/{{}} operation(s all) returned 0 exit status"),
 		n => error!("-exec/{{}} operation(s) returned non-zero exit code (total: {}) or were killed by signal", n),
 	    });
+	    rc
+	} else {
+	    0i32
+	}
+    } };
 
     // Now that transfer is complete from buffer to `stdout`, close `stdout` pipe before exiting process.
     if_trace!(info!("Transfer complete, closing `stdout` pipe"));
@@ -644,7 +658,9 @@ fn main() -> errors::DispersedResult<()> {
     }.wrap_err(eyre!("Failed to close stdout"))?;
 
     if rc != 0 {
-	if_trace!(error!("Exiting with non-zero code due to child(s) returning non-zero exit status")); //TODO: A flag to disable this? TODO: Also, a flag to stop printing to stdout so consumers of output can use just `-exec/{}` child process `stdout`s is enabled 
+	if cfg!(feature="exec") {
+	    if_trace!(error!("Exiting with non-zero code due to child(s) returning non-zero exit status")); //TODO: A runtime flag to disable this? TODO: Also, a flag to stop printing to stdout so consumers of output can use just `-exec/{}` child process `stdout`s is enabled
+	}
 	std::process::exit(rc);
     }