ouch 0.7.1

A command-line utility for easily compressing and decompressing files and directories.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219

//! Contains Tar-specific building and unpacking functions

#[cfg(unix)]
use std::os::unix::fs::MetadataExt;
use std::{
    collections::HashMap,
    env,
    io::{self, prelude::*},
    ops::Not,
    path::{Path, PathBuf},
};

use fs_err as fs;
use same_file::Handle;

use crate::{
    Result,
    error::FinalError,
    info,
    list::FileInArchive,
    utils::{
        self, BytesFmt, FileType, FileVisibilityPolicy, PathFmt, canonicalize, create_symlink, is_same_file_as_output,
        read_file_type, set_permission_mode,
    },
    warning,
};

/// Unpacks the archive given by `archive` into the folder given by `into`.
/// Assumes that output_folder is empty
pub fn unpack_archive(reader: impl Read, output_folder: &Path) -> Result<u64> {
    let mut archive = tar::Archive::new(reader);

    let mut files_unpacked = 0;
    let mut read_only_dirs_and_modes = Vec::new();

    for entry in archive.entries()? {
        let mut entry = entry?;

        match entry.header().entry_type() {
            tar::EntryType::Symlink => {
                let relative_path = entry.path()?;
                let full_path = output_folder.join(&relative_path);
                let target = entry
                    .link_name()?
                    .ok_or_else(|| io::Error::new(io::ErrorKind::InvalidData, "Missing symlink target"))?;

                create_symlink(&target, &full_path)?;
            }
            tar::EntryType::Link => {
                let link_path = entry.path()?;
                let target = entry
                    .link_name()?
                    .ok_or_else(|| io::Error::new(io::ErrorKind::InvalidData, "Missing hardlink target"))?;

                let full_link_path = output_folder.join(&link_path);
                let full_target_path = output_folder.join(&target);

                fs::hard_link(&full_target_path, &full_link_path)?;
            }
            tar::EntryType::Regular => {
                entry.unpack_in(output_folder)?;
            }
            tar::EntryType::Directory => {
                let original_mode = entry.header().mode()?;
                let is_writeable = (original_mode & 0o200) != 0;

                // this is no-op when dir already exists, errs if a file with another type is found there
                entry.unpack_in(output_folder)?;

                if cfg!(unix) && is_writeable.not() {
                    // We unpacked a read-only directory, make it writeable so that we can
                    // create the files inside of it, by the end, restore the original mode
                    let original_path = entry.path()?.to_path_buf();
                    let unpacked = output_folder.join(&original_path);
                    set_permission_mode(&unpacked, original_mode | 0o200)?;

                    read_only_dirs_and_modes.push((original_path, original_mode));
                }
            }
            _ => continue,
        }

        info!(
            "extracted ({}) {}",
            BytesFmt(entry.size()),
            PathFmt(&output_folder.join(entry.path()?)),
        );
        files_unpacked += 1;
    }

    // Restore original mode for read-only dirs we made writeable
    if cfg!(unix) {
        for (path, mode) in &read_only_dirs_and_modes {
            set_permission_mode(path, *mode)?;
        }
    }

    Ok(files_unpacked)
}

/// List contents of `archive`, returning a vector of archive entries
pub fn list_archive(mut archive: tar::Archive<impl Read>) -> Result<impl Iterator<Item = Result<FileInArchive>>> {
    let entries = archive.entries()?.map(|file| {
        let file = file?;
        let path = file.path()?.into_owned();
        let is_dir = file.header().entry_type().is_dir();
        Ok(FileInArchive { path, is_dir })
    });

    Ok(entries.collect::<Vec<_>>().into_iter())
}

/// Compresses the archives given by `input_filenames` into the file given previously to `writer`.
pub fn build_archive<W>(
    explicit_paths: &[PathBuf],
    output_path: &Path,
    writer: W,
    file_visibility_policy: FileVisibilityPolicy,
    follow_symlinks: bool,
) -> Result<W>
where
    W: Write,
{
    let mut builder = tar::Builder::new(writer);
    let output_handle = Handle::from_path(output_path);
    let mut seen_inode: HashMap<(u64, u64), PathBuf> = HashMap::new();

    for explicit_path in explicit_paths {
        let previous_location = utils::cd_into_same_dir_as(explicit_path)?;

        // Unwrap expectation:
        //   paths should be canonicalized by now, and the root directory rejected.
        let filename = explicit_path.file_name().unwrap();

        let iter = file_visibility_policy.workaround_build_walker_or_broken_link_path(explicit_path, filename);

        for entry in iter {
            let path = entry.unwrap();

            // Avoid compressing the output file into itself
            if let Ok(handle) = output_handle.as_ref()
                && is_same_file_as_output(&path, handle)
            {
                warning!("Cannot compress {} into itself, skipping", PathFmt(output_path));
                continue;
            }

            info!("Compressing {}", PathFmt(&path));

            let (metadata, file_type) = {
                if follow_symlinks {
                    (path.metadata()?, read_file_type(canonicalize(&path)?)?)
                } else {
                    (path.symlink_metadata()?, read_file_type(&path)?)
                }
            };

            // Treat unix hardlinks (ignore directory, since user-created directory hard links are
            // not a thing)
            //
            // TODO: to better support Windows hard links,
            // we should wait for this issue to be resolved:
            // https://github.com/rust-lang/rust/issues/63010
            #[cfg(unix)]
            if metadata.nlink() > 1 && !file_type.is_directory() {
                let inode_identifier = (metadata.dev(), metadata.ino());

                match seen_inode.get(&inode_identifier) {
                    Some(target_path) => {
                        let mut header = tar::Header::new_gnu();
                        header.set_entry_type(tar::EntryType::Link);
                        header.set_size(0);

                        builder.append_link(&mut header, &path, target_path).map_err(|err| {
                            FinalError::with_title("Could not create archive")
                                .detail(format!("Error appending hard link {}: {err}", PathFmt(&path)))
                        })?;
                        continue; // skip handling this file
                    }
                    None => {
                        // First time we see this file, let it be processed normally by the
                        // code below, but save it to this hashmap
                        seen_inode.insert(inode_identifier, path.to_path_buf());
                    }
                }
            }

            match file_type {
                FileType::Regular => {
                    let mut file = fs::File::open(&path)?;
                    builder.append_file(&path, file.file_mut()).map_err(|err| {
                        FinalError::with_title("Could not create archive")
                            .detail("Unexpected error while trying to read file")
                            .detail(format!("Error: {err}"))
                    })?;
                }
                FileType::Directory => {
                    builder.append_dir(&path, &path)?;
                }
                FileType::Symlink => {
                    let target_path = path.read_link()?;

                    let mut header = tar::Header::new_gnu();
                    header.set_entry_type(tar::EntryType::Symlink);
                    header.set_size(0);

                    builder.append_link(&mut header, &path, &target_path).map_err(|err| {
                        FinalError::with_title("Could not create archive")
                            .detail("Unexpected error while trying to read link")
                            .detail(format!("Error: {err}"))
                    })?;
                }
            }
        }
        env::set_current_dir(previous_location)?;
    }

    Ok(builder.into_inner()?)
}