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-rw-r--r--node_modules/cross-spawn/lib/util/readShebang.js37
1 files changed, 37 insertions, 0 deletions
diff --git a/node_modules/cross-spawn/lib/util/readShebang.js b/node_modules/cross-spawn/lib/util/readShebang.js
new file mode 100644
index 0000000..2cf3541
--- /dev/null
+++ b/node_modules/cross-spawn/lib/util/readShebang.js
@@ -0,0 +1,37 @@
+'use strict';
+
+var fs = require('fs');
+var LRU = require('lru-cache');
+var shebangCommand = require('shebang-command');
+
+var shebangCache = new LRU({ max: 50, maxAge: 30 * 1000 }); // Cache just for 30sec
+
+function readShebang(command) {
+ var buffer;
+ var fd;
+ var shebang;
+
+ // Check if it is in the cache first
+ if (shebangCache.has(command)) {
+ return shebangCache.get(command);
+ }
+
+ // Read the first 150 bytes from the file
+ buffer = new Buffer(150);
+
+ try {
+ fd = fs.openSync(command, 'r');
+ fs.readSync(fd, buffer, 0, 150, 0);
+ fs.closeSync(fd);
+ } catch (e) { /* empty */ }
+
+ // Attempt to extract shebang (null is returned if not a shebang)
+ shebang = shebangCommand(buffer.toString());
+
+ // Store the shebang in the cache
+ shebangCache.set(command, shebang);
+
+ return shebang;
+}
+
+module.exports = readShebang;