src/tools/systemd.rs: implement escape_unit and unescape_unit

This commit is contained in:
Dietmar Maurer 2020-06-09 11:52:06 +02:00
parent 9825748e5e
commit da84cc52f4

View File

@ -4,3 +4,71 @@ pub mod config;
mod parse_time;
pub mod tm_editor;
pub mod time;
use anyhow::{bail, Error};
/// Escape strings for usage in systemd unit names
pub fn escape_unit(mut unit: &str, is_path: bool) -> String {
if is_path {
unit = unit.trim_matches('/');
if unit.is_empty() {
return String::from("-");
}
}
let unit = unit.as_bytes();
let mut escaped = String::new();
for (i, c) in unit.iter().enumerate() {
if *c == b'/' {
escaped.push('-');
continue;
}
if (i == 0 && *c == b'.') || !((*c >= b'0' && *c <= b'9') || (*c >= b'A' && *c <= b'Z') || (*c >= b'a' && *c <= b'z')) {
escaped.push_str(&format!("\\x{:0x}", c));
} else {
escaped.push(*c as char);
}
}
escaped
}
fn parse_hex_digit(d: u8) -> Result<u8, Error> {
if d >= b'0' && d <= b'9' { return Ok(d - b'0'); }
if d >= b'A' && d <= b'F' { return Ok(d - b'A' + 10); }
if d >= b'a' && d <= b'f' { return Ok(d - b'a' + 10); }
bail!("got invalid hex digit");
}
/// Unescape strings used in systemd unit names
pub fn unescape_unit(text: &str) -> Result<String, Error> {
let mut i = text.as_bytes();
let mut data: Vec<u8> = Vec::new();
loop {
if i.is_empty() { break; }
let next = i[0];
if next == b'\\' {
if i.len() < 4 { bail!("short input"); }
if i[1] != b'x' { bail!("unkwnown escape sequence"); }
let h1 = parse_hex_digit(i[2])?;
let h0 = parse_hex_digit(i[3])?;
data.push(h1<<4|h0);
i = &i[4..]
} else if next == b'-' {
data.push(b'/');
i = &i[1..]
} else {
data.push(next);
i = &i[1..]
}
}
let text = String::from_utf8(data)?;
Ok(text)
}