From ab6f1b3e13c8e35667a245065131af51b71dd30a Mon Sep 17 00:00:00 2001
From: Max Kofler <kofler.max.dev@gmail.com>
Date: Fri, 8 Dec 2023 11:44:13 +0000
Subject: [PATCH] util::fs::script

---
 src/util/fs/fsentry.rs        | 14 +++++++++
 src/util/fs/fsentry/script.rs | 56 +++++++++++++++++++++++++++++++++++
 2 files changed, 70 insertions(+)
 create mode 100644 src/util/fs/fsentry/script.rs

diff --git a/src/util/fs/fsentry.rs b/src/util/fs/fsentry.rs
index 7516799..16a3277 100644
--- a/src/util/fs/fsentry.rs
+++ b/src/util/fs/fsentry.rs
@@ -15,11 +15,16 @@ pub use directory::*;
 mod elf;
 pub use elf::*;
 
+mod script;
+pub use script::*;
+
 /// A filesystem entry
 #[derive(Clone)]
 pub enum FSEntry {
     /// An ELF file
     ELF(ELFFile),
+    /// A script file
+    Script(ScriptFile),
     /// A symlink
     Symlink(OsString),
     /// Some other file
@@ -67,6 +72,14 @@ impl FSEntry {
                             .e_context(|| format!("Parsing ELF file {}", path.to_string_lossy()))?;
 
                         return Ok(Self::ELF(f));
+                    } else if infer::text::is_shellscript(&buf) {
+                        trace!("[infer] SCR : {}", &path.to_string_lossy());
+
+                        let f = ScriptFile::parse(&path, name).e_context(|| {
+                            format!("Parsing SCRIPT file {}", path.to_string_lossy())
+                        })?;
+
+                        return Ok(Self::Script(f));
                     }
                 }
             }
@@ -82,6 +95,7 @@ impl FSEntry {
     pub fn name(&self) -> &OsStr {
         match self {
             Self::ELF(n) => &n.name,
+            Self::Script(n) => &n.name,
             Self::Symlink(n) => n,
             Self::OtherFile(n) => n,
             Self::Directory(d) => &d.name,
diff --git a/src/util/fs/fsentry/script.rs b/src/util/fs/fsentry/script.rs
new file mode 100644
index 0000000..5b3c77f
--- /dev/null
+++ b/src/util/fs/fsentry/script.rs
@@ -0,0 +1,56 @@
+use std::{
+    collections::LinkedList,
+    ffi::OsString,
+    fs::File,
+    io::{BufRead, BufReader},
+    path::{Path, PathBuf},
+};
+
+use crate::error::{Error, ErrorExt};
+
+/// A fs entry that is a script (has a shbang at its start)
+#[derive(Clone)]
+pub struct ScriptFile {
+    /// The name of the file
+    pub name: OsString,
+
+    /// The interpreter for the file
+    /// (<path to the interpreter>, <array of arguments>)
+    pub interpreter: Option<(PathBuf, Vec<OsString>)>,
+}
+
+impl ScriptFile {
+    /// Parses an `ELFFile` from the provided path
+    /// # Arguments
+    /// * `path` - The path to parse the file from
+    pub fn parse(path: &Path, name: OsString) -> Result<Self, Error> {
+        let context = || format!("Parsing SCRIPT file {}", path.to_string_lossy());
+
+        // Read the first line
+        let first_line = {
+            let mut file = BufReader::new(File::open(path).e_context(context)?);
+            let mut shbang = String::new();
+            file.read_line(&mut shbang).e_context(context)?;
+            shbang
+        };
+
+        // Remove the shbang from the start ('#!')
+        let first_line = first_line.trim_start_matches("#!");
+
+        // Split the line into its pieces
+        let mut split: LinkedList<OsString> = first_line
+            .split(' ')
+            .map(|s| OsString::from(s.trim()))
+            .collect();
+
+        // Split the interpreter path from its arguments
+        let interpreter = split.pop_front().map(|i| {
+            (
+                PathBuf::from(i),
+                split.into_iter().collect::<Vec<OsString>>(),
+            )
+        });
+
+        Ok(Self { name, interpreter })
+    }
+}