Attempt to detect when an archiver does not exist (HACK!)

core/archive_util.js

@@ -2,12 +2,12 @@
 'use strict';
 
 //	ENiGMA½
-let Config		= require('./config.js').config;
+const Config	= require('./config.js').config;
 
 //	base/modules
-let fs			= require('fs');
-let _			= require('lodash');
-let pty			= require('ptyw.js');
+const fs		= require('fs');
+const _			= require('lodash');
+const pty		= require('ptyw.js');
 
 module.exports = class ArchiveUtil {
 	
@@ -74,15 +74,14 @@ module.exports = class ArchiveUtil {
 			let buf = new Buffer(this.longestSignature);
 			fs.read(fd, buf, 0, buf.length, 0, (err, bytesRead) => {
 				if(err) {
-					cb(err);
-					return;
+					return cb(err);
 				}
 
 				//	return first match
 				const detected = _.findKey(this.archivers, arch => {
 					const lenNeeded = arch.offset + arch.sig.length;
 					
-					if(buf.length < lenNeeded) {
+					if(bytesRead < lenNeeded) {
 						return false;
 					}
 
@@ -95,6 +94,27 @@ module.exports = class ArchiveUtil {
 		});
 	}
 
+	spawnHandler(comp, action, cb) {
+		//	pty.js doesn't currently give us a error when things fail,
+		//	so we have this horrible, horrible hack:
+		let err;
+		comp.once('data', d => {
+			if(_.isString(d) && d.startsWith('execvp(3) failed.: No such file or directory')) {
+				err = new Error(`${action} failed: ${d.trim()}`);
+			}
+		});
+		
+		comp.once('exit', exitCode => {
+			if(exitCode) {
+				return cb(new Error(`${action} failed with exit code: ${exitCode}`));
+			}
+			if(err) {
+				return cb(err);
+			}
+			return cb(null);
+		});	
+	}
+
 	compressTo(archType, archivePath, files, cb) {
 		const archiver = this.getArchiver(archType);
 		
@@ -112,9 +132,7 @@ module.exports = class ArchiveUtil {
 
 		let comp = pty.spawn(archiver.compressCmd, args, this.getPtyOpts());
 
-		comp.once('exit', exitCode => {
-			cb(exitCode ? new Error(`Compression failed with exit code: ${exitCode}`) : null);
-		});
+		return this.spawnHandler(comp, 'Compression', cb);
 	}
 
 	extractTo(archivePath, extractPath, archType, cb) {
@@ -133,10 +151,8 @@ module.exports = class ArchiveUtil {
 		}
 		
 		let comp = pty.spawn(archiver.decompressCmd, args, this.getPtyOpts());
-		
-		comp.once('exit', exitCode => {
-			cb(exitCode ? new Error(`Decompression failed with exit code: ${exitCode}`) : null);
-		});		
+
+		return this.spawnHandler(comp, 'Decompression', cb);
 	}
 	
 	getPtyOpts() {
@@ -148,4 +164,4 @@ module.exports = class ArchiveUtil {
 			env		: process.env,	
 		};
 	}
-}
+};