chmod_calculator 0.1.0

A tool for calculating chmod octal values and rwx style valus
Documentation 
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
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236


/// Parses an octal string
///
/// ```
/// use chmod_calculator::parse_octal_string;
///
/// assert_eq!("765", parse_octal_string("765".to_string()).unwrap());
/// assert_eq!("765", parse_octal_string("0765".to_string()).unwrap());
/// ```
pub fn parse_octal_string(input: String) -> Result<String, &'static str> {
  match input.parse::<i32>() {
    Ok(parsed_number) => {
      if (parsed_number < 0) || (parsed_number > 777) {
        return Err("Invalid value");
      }

      return Ok(parsed_number.to_string());
    }
    Err(_err) => Err("Not a number"),
  }
}

/// Converts an octal chmod value to a rwx string
///
/// ```
/// use chmod_calculator::octal_string_to_rwx_string;
///
/// assert_eq!("--x-w--wx", octal_string_to_rwx_string("123".to_string()).unwrap());
/// assert_eq!("rwxrw-r-x", octal_string_to_rwx_string("765".to_string()).unwrap());
/// ```
pub fn octal_string_to_rwx_string(input: String) -> Result<String, &'static str> {
  if input.len() != 3 {
    return Err("Invalid value");
  }

  let mut rwx_string = String::new();

  for c in input.chars() {
    match c {
      '7' => rwx_string.push_str("rwx"),
      '6' => rwx_string.push_str("rw-"),
      '5' => rwx_string.push_str("r-x"),
      '4' => rwx_string.push_str("r--"),
      '3' => rwx_string.push_str("-wx"),
      '2' => rwx_string.push_str("-w-"),
      '1' => rwx_string.push_str("--x"),
      '0' => rwx_string.push_str("---"),
      _ => {
        return Err("Invalid character");
      }
    }
  }

  return Ok(rwx_string.to_string());
}

/// Converts a rwx string to an octal chmod value
///
/// ```
/// use chmod_calculator::rwx_string_to_octal_string;
///
/// assert_eq!("137", rwx_string_to_octal_string("--x-wxrwx".to_string()).unwrap());
/// assert_eq!("765", rwx_string_to_octal_string("rwxrw-r-x".to_string()).unwrap());
/// ```
pub fn rwx_string_to_octal_string(input: String) -> Result<String, &'static str> {
  if input.len() != 9 {
    return Err("Invalid value");
  }

  let mut octal_string = String::new();

  // Split up the user, group, other parts
  let mut parts = Vec::new();
  parts.push(&input[0..3]);
  parts.push(&input[3..6]);
  parts.push(&input[6..9]);

  for p in parts {
    let p_string: String = p.to_string();
    match p_string.as_str() {
      "rwx" => octal_string.push('7'),
      "rw-" => octal_string.push('6'),
      "r-x" => octal_string.push('5'),
      "r--" => octal_string.push('4'),
      "-wx" => octal_string.push('3'),
      "-w-" => octal_string.push('2'),
      "--x" => octal_string.push('1'),
      "---" => octal_string.push('0'),
      _ => {
        println!("Err {}", p_string);
        return Err("Invalid characters");
      }
    }
  }

  return Ok(octal_string.to_string());
}

/// Prints out an rwx string as a table
///
/// Output:
///         Owner  Group Other
/// Read    x      x     x
/// Write   x      x
/// Execute x            x
///
/// ```
/// use chmod_calculator::rwx_string_to_table;
///
/// assert_eq!("        Owner  Group Other\n\
///    Read                 x\n\
///    Write          x     x\n\
///    Execute x      x     x", rwx_string_to_table("--x-wxrwx".to_string()).unwrap());
/// ```
pub fn rwx_string_to_table(input: String) -> Result<String, &'static str> {
  let mut x_and_spaces = String::new();

  for c in input.chars() { 
    match c {
      'w' | 'r' | 'x' => {
        x_and_spaces.push('x');
      }
      _ => {
        x_and_spaces.push(' ');
      }
    }
  }

  // There must be a better way to do this
  let output = format!(
    "        Owner  Group Other\n\
    Read    {}      {}     {}\n\
    Write   {}      {}     {}\n\
    Execute {}      {}     {}",
    x_and_spaces.chars().nth(0).expect("Not enough characters").to_string(), x_and_spaces.chars().nth(3).expect("Not enough characters").to_string(), x_and_spaces.chars().nth(6).expect("Not enough characters").to_string(),
    x_and_spaces.chars().nth(1).expect("Not enough characters").to_string(), x_and_spaces.chars().nth(4).expect("Not enough characters").to_string(), x_and_spaces.chars().nth(7).expect("Not enough characters").to_string(),
    x_and_spaces.chars().nth(2).expect("Not enough characters").to_string(), x_and_spaces.chars().nth(5).expect("Not enough characters").to_string(), x_and_spaces.chars().nth(8).expect("Not enough characters").to_string()
  );

  return Ok(output);
}

// 765
// rwxrw-r-x
// $ ./chmod-calculator 0765
// rwxrw-r-x
// $ ./chmod-calculator rwxrw-r-x
// 765
// $ ./chmod-calculator --table 765

pub fn convert(input: String, table: bool) -> Result<String, &'static str> {
  match parse_octal_string(input.to_string()) {
    Ok(octal_value)  => {
      // Octal string
      let rwx_string = octal_string_to_rwx_string(octal_value);
      if table {
        return rwx_string_to_table(rwx_string.unwrap());
      } else {
        return rwx_string;
      }
    }
    Err(_e) => {
      // rwx string
      let rwx_string = input;
      if table {
        return rwx_string_to_table(rwx_string.to_string());
      } else {
        return rwx_string_to_octal_string(rwx_string);
      }
    }
  };
}


// This entire test module will be excluded from the normal builds. Tests don't actually
// _need_ to be inside of a test module like this, but it does make it easier to keep things
// clean and organized.
#[cfg(test)]
mod test {
  use super::parse_octal_string;
  use super::octal_string_to_rwx_string;
  use super::rwx_string_to_octal_string;
  use super::rwx_string_to_table;

  #[test]
  fn parse_octal_string_parses_numbers() {
    assert_eq!("765", parse_octal_string("765".to_string()).unwrap());
    assert_eq!("765", parse_octal_string("0765".to_string()).unwrap());

    // Failure conditions
    assert_eq!(Err("Not a number"), parse_octal_string("".to_string()));
    assert_eq!(Err("Not a number"), parse_octal_string("asfdasdds".to_string()));
    assert_eq!(Err("Not a number"), parse_octal_string("--x-wxrwx".to_string()));
    assert_eq!(Err("Invalid value"), parse_octal_string("-5".to_string()));
    assert_eq!(Err("Invalid value"), parse_octal_string("789".to_string())); // Digits with a value greater than 7
    assert_eq!(Err("Invalid value"), parse_octal_string("5000".to_string())); // Too many digits
  }

  #[test]
  fn octal_string_to_rwx_string_converts() {
    assert_eq!("--x-w--wx", octal_string_to_rwx_string("123".to_string()).unwrap());
    assert_eq!("rwxrw-r-x", octal_string_to_rwx_string("765".to_string()).unwrap());

    // Failure conditions
    assert_eq!(Err("Invalid value"), octal_string_to_rwx_string("".to_string()));
    assert_eq!(Err("Invalid value"), octal_string_to_rwx_string("asfdasdds".to_string()));
    assert_eq!(Err("Invalid value"), octal_string_to_rwx_string("--x-wxrwx".to_string()));
    assert_eq!(Err("Invalid value"), octal_string_to_rwx_string("-5".to_string()));
    assert_eq!(Err("Invalid value"), octal_string_to_rwx_string("0765".to_string())); // 0 should have been stripped before calling this function
    assert_eq!(Err("Invalid character"), octal_string_to_rwx_string("789".to_string())); // Digits with a value greater than 7
    assert_eq!(Err("Invalid value"), octal_string_to_rwx_string("5000".to_string()));
  }

  #[test]
  fn rwx_string_to_octal_string_converts() {
    assert_eq!("137", rwx_string_to_octal_string("--x-wxrwx".to_string()).unwrap());
    assert_eq!("765", rwx_string_to_octal_string("rwxrw-r-x".to_string()).unwrap());

    // Failure conditions
    assert_eq!(Err("Invalid value"), rwx_string_to_octal_string("0765".to_string()));
    assert_eq!(Err("Invalid value"), rwx_string_to_octal_string("".to_string()));
    assert_eq!(Err("Invalid characters"), rwx_string_to_octal_string("asfdasdds".to_string())); // Invalid characters
    assert_eq!(Err("Invalid value"), rwx_string_to_octal_string("---x-wxrwx".to_string())); // Too many characters
    assert_eq!(Err("Invalid value"), rwx_string_to_octal_string("-x-wxrwx".to_string())); // Not enough characters
    assert_eq!(Err("Invalid value"), rwx_string_to_octal_string("-5".to_string()));
    assert_eq!(Err("Invalid value"), rwx_string_to_octal_string("5000".to_string()));
  }

  #[test]
  fn rwx_string_to_table_generates() {
    assert_eq!("        Owner  Group Other\n\
    Read                 x\n\
    Write          x     x\n\
    Execute x      x     x", rwx_string_to_table("--x-wxrwx".to_string()).unwrap());
  }
}