Allow specification of mode strings for install

We now accept symbolic and numeric mode strings using the
--mode or -m option for install.  This is used either when
moving files into a directory, or when creating component
directories with the -d option.  This feature was designed
to mirror the GNU implementation, including the possibly
quirky behaviour of `install --mode=u+wx file dir`
resulting in dir/file having exactly permissions 0300.

Extensive integration tests are included.

This chnage required a higher libc dependency.

Cargo.lock

@@ -426,7 +426,7 @@ name = "install"
 version = "0.0.1"
 dependencies = [
  "getopts 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.1.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "uucore 0.0.1",
 ]
 

src/install/Cargo.toml

@@ -9,7 +9,7 @@ path = "install.rs"
 
 [dependencies]
 getopts = "*"
-libc = "*"
+libc = ">= 0.2"
 uucore = { path="../uucore" }
 
 [dev-dependencies]

src/install/install.rs

@@ -12,21 +12,26 @@
 extern crate getopts;
 extern crate libc;
 
+mod mode;
+
 #[macro_use]
 extern crate uucore;
 
 use std::fs;
-use std::io::{Write};
+use std::io::Write;
 use std::path::{Path, PathBuf};
 use std::result::Result;
 
 static NAME: &'static str = "install";
 static VERSION: &'static str = env!("CARGO_PKG_VERSION");
 
+const DEFAULT_MODE: libc::mode_t = 755;
+
 pub struct Behaviour {
     main_function: MainFunction,
+    specified_mode: Option<u16>,
     suffix: String,
-    verbose: bool,
+    verbose: bool
 }
 
 #[derive(Clone, Eq, PartialEq)]
@@ -41,6 +46,16 @@ pub enum MainFunction {
     Standard
 }
 
+impl Behaviour {
+    /// Determine the mode for chmod after copy.
+    pub fn mode(&self) -> libc::mode_t {
+        match self.specified_mode {
+            Some(x) => x,
+            None => DEFAULT_MODE
+        }
+    }
+}
+
 /// Main install utility function, called from main.rs.
 ///
 /// Returns a program return code.
@@ -129,8 +144,7 @@ fn opts() -> getopts::Options {
     opts.optflagopt("g", "group", "(unimplemented) set group ownership, instead of process'\n \
                                    current group", "GROUP");
 
-    // TODO implement flag
-    opts.optflagopt("m", "mode", "(unimplemented) set permission mode (as in chmod), instead\n \
+    opts.optflagopt("m", "mode", "set permission mode (as in chmod), instead\n \
                                   of rwxr-xr-x", "MODE");
 
     // TODO implement flag
@@ -193,8 +207,6 @@ fn check_unimplemented(matches: &getopts::Matches) -> Result<(), &str> {
         Err("-D")
     } else if matches.opt_present("group") {
         Err("--group, -g")
-    } else if matches.opt_present("mode") {
-        Err("--mode, -m")
     } else if matches.opt_present("owner") {
         Err("--owner, -o")
     } else if matches.opt_present("preserve-timestamps") {
@@ -239,6 +251,29 @@ fn behaviour(matches: &getopts::Matches) -> Result<Behaviour, i32> {
         MainFunction::Standard
     };
 
+    let considering_dir: bool = MainFunction::Directory == main_function;
+
+    let specified_mode: Option<libc::mode_t> = if matches.opt_present("mode") {
+        match matches.opt_str("mode") {
+            Some(x) => {
+                match mode::parse(&x[..], considering_dir) {
+                    Ok(y) => Some(y),
+                    Err(err) => {
+                        show_error!("Invalid mode string: {}", err);
+                        return Err(1);
+                    }
+                }
+            },
+            None => {
+                show_error!("option '--mode' requires an argument\n \
+                            Try '{} --help' for more information.", NAME);
+                return Err(1);
+            }
+        }
+    } else {
+        None
+    };
+
     let backup_suffix = if matches.opt_present("suffix") {
         match matches.opt_str("suffix") {
             Some(x) => x,
@@ -254,6 +289,7 @@ fn behaviour(matches: &getopts::Matches) -> Result<Behaviour, i32> {
 
     Ok(Behaviour {
         main_function: main_function,
+        specified_mode: specified_mode,
         suffix: backup_suffix,
         verbose: matches.opt_present("v"),
     })
@@ -295,6 +331,10 @@ fn directory(paths: &[PathBuf], b: Behaviour) -> i32 {
                 all_successful = false;
             }
 
+            if mode::chmod(&path, b.mode()).is_err() {
+                all_successful = false;
+            }
+
             if b.verbose {
                 show_info!("created directory '{}'", path.display());
             }
@@ -355,7 +395,7 @@ fn copy_files_into_dir(files: &[PathBuf], target_dir: &PathBuf, b: &Behaviour) -
     if all_successful { 0 } else { 1 }
 }
 
-/// Copy one file to a new location.
+/// Copy one file to a new location, changing metadata.
 ///
 /// # Parameters
 ///
@@ -372,7 +412,11 @@ fn copy(from: &PathBuf, to: &PathBuf, b: &Behaviour) -> Result<(), ()> {
     if let Err(err) = io_result {
         show_error!("install: cannot install ‘{}’ to ‘{}’: {}",
                     from.display(), to.display(), err);
-        return Err(())
+        return Err(());
+    }
+
+    if mode::chmod(&to, b.mode()).is_err() {
+        return Err(());
     }
 
     if b.verbose {

src/install/mode.rs

@@ -0,0 +1,166 @@
+extern crate libc;
+
+use std::io::Write;
+use std::path::{Path, PathBuf};
+
+/// Takes a user-supplied string and tries to parse to u16 mode bitmask.
+pub fn parse(mode_string: &str, considering_dir: bool) -> Result<libc::mode_t, String> {
+    let numbers: &[char] = &['0', '1', '2', '3', '4', '5', '6', '7', '8', '9'];
+
+    // Passing 000 as the existing permissions seems to mirror GNU behaviour.
+    if mode_string.contains(numbers) {
+        chmod_rs::parse_numeric(0, mode_string)
+    } else {
+        chmod_rs::parse_symbolic(0, mode_string, considering_dir)
+    }
+}
+
+/// chmod a file or directory on UNIX.
+///
+/// Adapted from mkdir.rs.  Handles own error printing.
+///
+#[cfg(unix)]
+pub fn chmod(path: &Path, mode: libc::mode_t) -> Result<(), ()> {
+    use std::ffi::CString;
+    use std::io::Error;
+
+    let file = CString::new(path.as_os_str().to_str().unwrap()).
+                            unwrap_or_else(|e| crash!(1, "{}", e));
+    let mode = mode as libc::mode_t;
+
+    if unsafe { libc::chmod(file.as_ptr(), mode) } != 0 {
+        show_info!("{}: chmod failed with errno {}", path.display(),
+                   Error::last_os_error().raw_os_error().unwrap());
+        return Err(());
+    }
+    Ok(())
+}
+
+/// chmod a file or directory on Windows.
+///
+/// Adapted from mkdir.rs.
+///
+#[cfg(windows)]
+pub fn chmod(path: &Path, mode: libc::mode_t) -> Result<(), ()> {
+    // chmod on Windows only sets the readonly flag, which isn't even honored on directories
+    Ok(())
+}
+
+/// Parsing functions taken from chmod.rs.
+///
+/// We keep these in a dedicated module to minimize debt of duplicated code.
+///
+mod chmod_rs {
+    extern crate libc;
+
+    pub fn parse_numeric(fperm: libc::mode_t, mut mode: &str) -> Result<libc::mode_t, String> {
+        let (op, pos) = try!(parse_op(mode, Some('=')));
+        mode = mode[pos..].trim_left_matches('0');
+        if mode.len() > 4 {
+            Err(format!("mode is too large ({} > 7777)", mode))
+        } else {
+            match libc::mode_t::from_str_radix(mode, 8) {
+                Ok(change) => {
+                    Ok(match op {
+                        '+' => fperm | change,
+                        '-' => fperm & !change,
+                        '=' => change,
+                        _ => unreachable!()
+                    })
+                }
+                Err(err) => Err(String::from("numeric parsing error"))
+            }
+        }
+    }
+
+    pub fn parse_symbolic(mut fperm: libc::mode_t, mut mode: &str, considering_dir: bool) -> Result<libc::mode_t, String> {
+        let (mask, pos) = parse_levels(mode);
+        if pos == mode.len() {
+            return Err(format!("invalid mode ({})", mode));
+        }
+        let respect_umask = pos == 0;
+        let last_umask = unsafe {
+            libc::umask(0)
+        };
+        mode = &mode[pos..];
+        while mode.len() > 0 {
+            let (op, pos) = try!(parse_op(mode, None));
+            mode = &mode[pos..];
+            let (mut srwx, pos) = parse_change(mode, fperm, considering_dir);
+            if respect_umask {
+                srwx &= !last_umask;
+            }
+            mode = &mode[pos..];
+            match op {
+                '+' => fperm |= srwx & mask,
+                '-' => fperm &= !(srwx & mask),
+                '=' => fperm = (fperm & !mask) | (srwx & mask),
+                _ => unreachable!()
+            }
+        }
+        unsafe {
+            libc::umask(last_umask);
+        }
+        Ok(fperm)
+    }
+
+    fn parse_levels(mode: &str) -> (libc::mode_t, usize) {
+        let mut mask = 0;
+        let mut pos = 0;
+        for ch in mode.chars() {
+            mask |= match ch {
+                'u' => 0o7700,
+                'g' => 0o7070,
+                'o' => 0o7007,
+                'a' => 0o7777,
+                _ => break
+            };
+            pos += 1;
+        }
+        if pos == 0 {
+            mask = 0o7777;  // default to 'a'
+        }
+        (mask, pos)
+    }
+
+    fn parse_op(mode: &str, default: Option<char>) -> Result<(char, usize), String> {
+        match mode.chars().next() {
+            Some(ch) => match ch {
+                '+' | '-' | '=' => Ok((ch, 1)),
+                _ => match default {
+                    Some(ch) => Ok((ch, 0)),
+                    None => Err(format!("invalid operator (expected +, -, or =, but found {})", ch))
+                }
+            },
+            None => Err("unexpected end of mode".to_owned())
+        }
+    }
+
+    fn parse_change(mode: &str, fperm: libc::mode_t, considering_dir: bool) -> (libc::mode_t, usize) {
+        let mut srwx = fperm & 0o7000;
+        let mut pos = 0;
+        for ch in mode.chars() {
+            match ch {
+                'r' => srwx |= 0o444,
+                'w' => srwx |= 0o222,
+                'x' => srwx |= 0o111,
+                'X' => {
+                    if considering_dir || (fperm & 0o0111) != 0 {
+                        srwx |= 0o111
+                    }
+                }
+                's' => srwx |= 0o4000 | 0o2000,
+                't' => srwx |= 0o1000,
+                'u' => srwx = (fperm & 0o700) | ((fperm >> 3) & 0o070) | ((fperm >> 6) & 0o007),
+                'g' => srwx = ((fperm << 3) & 0o700) | (fperm & 0o070) | ((fperm >> 3) & 0o007),
+                'o' => srwx = ((fperm << 6) & 0o700) | ((fperm << 3) & 0o070) | (fperm & 0o007),
+                _ => break
+            };
+            pos += 1;
+        }
+        if pos == 0 {
+            srwx = 0;
+        }
+        (srwx, pos)
+    }
+}

tests/test_install.rs

@@ -6,6 +6,7 @@ extern crate filetime;
 
 use self::filetime::*;
 use common::util::*;
+use std::os::unix::fs::PermissionsExt;
 
 static UTIL_NAME: &'static str = "install";
 
@@ -89,3 +90,81 @@ fn test_install_component_directories_failing() {
     assert!(!result.success);
     assert!(result.stderr.contains("File exists"));
 }
+
+#[test]
+fn test_install_mode_numeric() {
+    let (at, mut ucmd) = testing(UTIL_NAME);
+    let dir = "test_install_target_dir_dir_e";
+    let file = "test_install_target_dir_file_e";
+    let mode_arg = "--mode=333";
+
+    at.touch(file);
+    at.mkdir(dir);
+    let result = ucmd.arg(file).arg(dir).arg(mode_arg).run();
+
+    assert!(result.success);
+    assert_empty_stderr!(result);
+
+    let dest_file = &format!("{}/{}", dir, file);
+    assert!(at.file_exists(file));
+    assert!(at.file_exists(dest_file));
+    let permissions = at.metadata(dest_file).permissions();
+    assert_eq!(0o333 as u32, PermissionsExt::mode(&permissions));
+}
+
+#[test]
+fn test_install_mode_symbolic() {
+    let (at, mut ucmd) = testing(UTIL_NAME);
+    let dir = "test_install_target_dir_dir_f";
+    let file = "test_install_target_dir_file_f";
+    let mode_arg = "--mode=o+wx";
+
+    at.touch(file);
+    at.mkdir(dir);
+    let result = ucmd.arg(file).arg(dir).arg(mode_arg).run();
+
+    assert!(result.success);
+    assert_empty_stderr!(result);
+
+    let dest_file = &format!("{}/{}", dir, file);
+    assert!(at.file_exists(file));
+    assert!(at.file_exists(dest_file));
+    let permissions = at.metadata(dest_file).permissions();
+    assert_eq!(0o003 as u32, PermissionsExt::mode(&permissions));
+}
+
+#[test]
+fn test_install_mode_failing() {
+    let (at, mut ucmd) = testing(UTIL_NAME);
+    let dir = "test_install_target_dir_dir_g";
+    let file = "test_install_target_dir_file_g";
+    let mode_arg = "--mode=999";
+
+    at.touch(file);
+    at.mkdir(dir);
+    let result = ucmd.arg(file).arg(dir).arg(mode_arg).run();
+
+    assert!(!result.success);
+    assert!(result.stderr.contains("Invalid mode string: numeric parsing error"));
+
+    let dest_file = &format!("{}/{}", dir, file);
+    assert!(at.file_exists(file));
+    assert!(!at.file_exists(dest_file));
+}
+
+#[test]
+fn test_install_mode_directories() {
+    let (at, mut ucmd) = testing(UTIL_NAME);
+    let component = "test_install_target_dir_component_h";
+    let directories_arg = "-d";
+    let mode_arg = "--mode=333";
+
+    let result = ucmd.arg(directories_arg).arg(component).arg(mode_arg).run();
+
+    assert!(result.success);
+    assert_empty_stderr!(result);
+
+    assert!(at.dir_exists(component));
+    let permissions = at.metadata(component).permissions();
+    assert_eq!(0o333 as u32, PermissionsExt::mode(&permissions));
+}