apipe 0.2.0

An anonymous UNIX pipe type.
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

//! Abstraction over an external command.

use crate::pipe::CommandPipe;
use std::{ffi::OsStr, ops};

#[cfg(feature = "parser")]
use lazy_static::lazy_static;
#[cfg(feature = "parser")]
use regex::Regex;

#[cfg(feature = "parser")]
type Result<T> = std::result::Result<T, crate::error::APipeError>;

/// Abstraction of an external command.
///
/// ## Example
///
/// ```
/// # use apipe::{Command, error::APipeError};
/// # fn main() -> Result<(), APipeError> {
/// let cmd = Command::parse_str(r#"grep -Eo "\w\w\sa[^.]*""#)?;
///
/// // or
///
/// let cmd = Command::new("grep").args(&["-Eo", r"\w\w\sa[^.]*"]);
/// # Ok(())
/// # }
/// ```
#[derive(Debug)]
pub struct Command(pub(crate) std::process::Command);

impl<T> From<T> for Command
where
    T: AsRef<OsStr>,
{
    fn from(s: T) -> Self {
        Command(std::process::Command::new(s))
    }
}

impl ops::BitOr<Command> for Command {
    type Output = CommandPipe;

    fn bitor(self, rhs: Self) -> CommandPipe {
        let mut pipe = CommandPipe::new();
        pipe.pipeline.push(self);
        pipe.pipeline.push(rhs);

        pipe
    }
}

impl Command {
    /// Creates a new command instance.
    ///
    /// ## Example
    ///
    /// ```
    /// # use apipe::Command;
    /// let cmd = Command::new("ls");
    /// ```
    pub fn new<S>(command: S) -> Self
    where
        S: AsRef<OsStr>,
    {
        Command(std::process::Command::new(command))
    }

    /// Adds a single argument to an existing Command instance.
    ///
    /// ## Example
    ///
    /// ```
    /// # use apipe::Command;
    /// let cmd = Command::new("ls").arg("-la");
    /// ```
    pub fn arg<S>(mut self, arg: S) -> Self
    where
        S: AsRef<OsStr>,
    {
        self.0.arg(arg);
        self
    }

    /// Adds a multiple arguments to an existing Command instance.
    ///
    /// ## Example
    ///
    /// ```
    /// # use apipe::Command;
    /// let cmd = Command::new("grep").args(&["-Eo", r"\w\w\sa[^.]*"]);
    /// ```
    pub fn args<S, I>(mut self, args: I) -> Self
    where
        I: IntoIterator<Item = S>,
        S: AsRef<OsStr>,
    {
        self.0.args(args);
        self
    }

    #[cfg(feature = "parser")]
    /// Constructs a Command from a string including the program and its args.
    ///
    /// ## Example
    ///
    /// ```
    /// # use apipe::{cmd::Command, error::APipeError};
    /// # fn main() -> Result<(), APipeError> {
    ///     let cmd = Command::parse_str(r#"grep -Eo "\w\w\sa[^.]*""#)?;
    /// # Ok(())
    /// # }
    /// ```
    pub fn parse_str(c: &str) -> Result<Self> {
        lazy_static! {
            static ref RE: Regex = Regex::new(r#"([^\s"']+)|("[^"]*?")|('[^']*?')"#).unwrap();
        }

        let matches = RE.captures_iter(c);
        let cmd_parts: Vec<&str> = matches.map(|x| x.get(0).unwrap().as_str()).collect();

        let (&cmd, args) = cmd_parts
            .split_first()
            .ok_or_else(|| crate::error::APipeError::Parser(c.to_owned()))?;

        let command = Command::new(cmd).args(args);

        Ok(command)
    }
}

#[cfg(all(test, feature = "parser"))]
mod tests {
    use super::*;

    #[test]
    fn test_literal_pipe() -> Result<()> {
        let pipe = Command::parse_str(r#"echo "This is a test.""#)?
            | Command::parse_str(r#"grep -Eo "\w\w\sa[^.]*""#)?
            | Command::parse_str(r#"sed "s/test/TEST/""#)?;

        assert_eq!(pipe.pipeline[0].0.get_program(), "echo");
        assert_eq!(
            pipe.pipeline[0].0.get_args().collect::<Vec<&OsStr>>(),
            &[r#""This is a test.""#]
        );
        assert_eq!(pipe.pipeline[1].0.get_program(), "grep");
        assert_eq!(
            pipe.pipeline[1].0.get_args().collect::<Vec<&OsStr>>(),
            &["-Eo", r#""\w\w\sa[^.]*""#]
        );
        assert_eq!(pipe.pipeline[2].0.get_program(), "sed");
        assert_eq!(
            pipe.pipeline[2].0.get_args().collect::<Vec<&OsStr>>(),
            &[r#""s/test/TEST/""#]
        );

        Ok(())
    }
}