use nu_cmd_base::input_handler::{CmdArgument, operate};
use nu_engine::command_prelude::*;
struct Arguments {
pattern: Vec<u8>,
end: bool,
all: bool,
cell_paths: Option<Vec<CellPath>>,
}
impl CmdArgument for Arguments {
fn take_cell_paths(&mut self) -> Option<Vec<CellPath>> {
self.cell_paths.take()
}
}
#[derive(Clone)]
pub struct BytesIndexOf;
impl Command for BytesIndexOf {
fn name(&self) -> &str {
"bytes index-of"
}
fn signature(&self) -> Signature {
Signature::build("bytes index-of")
.input_output_types(vec![
(Type::Binary, Type::Any),
(Type::table(), Type::table()),
(Type::record(), Type::record()),
])
.allow_variants_without_examples(true)
.required(
"pattern",
SyntaxShape::Binary,
"The pattern to find index of.",
)
.rest(
"rest",
SyntaxShape::CellPath,
"For a data structure input, find the indexes at the given cell paths.",
)
.switch("all", "Returns all matched index.", Some('a'))
.switch("end", "Search from the end of the binary.", Some('e'))
.category(Category::Bytes)
}
fn description(&self) -> &str {
"Returns start index of first occurrence of pattern in bytes, or -1 if no match."
}
fn search_terms(&self) -> Vec<&str> {
vec!["pattern", "match", "find", "search"]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let pattern: Vec<u8> = call.req(engine_state, stack, 0)?;
let cell_paths: Vec<CellPath> = call.rest(engine_state, stack, 1)?;
let cell_paths = (!cell_paths.is_empty()).then_some(cell_paths);
let arg = Arguments {
pattern,
end: call.has_flag(engine_state, stack, "end")?,
all: call.has_flag(engine_state, stack, "all")?,
cell_paths,
};
operate(index_of, arg, input, call.head, engine_state.signals())
}
fn examples(&self) -> Vec<Example<'_>> {
vec![
Example {
description: "Returns index of pattern in bytes.",
example: " 0x[33 44 55 10 01 13 44 55] | bytes index-of 0x[44 55]",
result: Some(Value::test_int(1)),
},
Example {
description: "Returns index of pattern, search from end.",
example: " 0x[33 44 55 10 01 13 44 55] | bytes index-of --end 0x[44 55]",
result: Some(Value::test_int(6)),
},
Example {
description: "Returns all matched index.",
example: " 0x[33 44 55 10 01 33 44 33 44] | bytes index-of --all 0x[33 44]",
result: Some(Value::test_list(vec![
Value::test_int(0),
Value::test_int(5),
Value::test_int(7),
])),
},
Example {
description: "Returns all matched index, searching from end.",
example: " 0x[33 44 55 10 01 33 44 33 44] | bytes index-of --all --end 0x[33 44]",
result: Some(Value::test_list(vec![
Value::test_int(7),
Value::test_int(5),
Value::test_int(0),
])),
},
Example {
description: "Returns index of pattern for specific column.",
example: " [[ColA ColB ColC]; [0x[11 12 13] 0x[14 15 16] 0x[17 18 19]]] | bytes index-of 0x[11] ColA ColC",
result: Some(Value::test_list(vec![Value::test_record(record! {
"ColA" => Value::test_int(0),
"ColB" => Value::binary(vec![0x14, 0x15, 0x16], Span::test_data()),
"ColC" => Value::test_int(-1),
})])),
},
]
}
}
fn index_of(val: &Value, args: &Arguments, span: Span) -> Value {
let val_span = val.span();
match val {
Value::Binary { val, .. } => index_of_impl(val, args, val_span),
Value::Error { .. } => val.clone(),
other => Value::error(
ShellError::OnlySupportsThisInputType {
exp_input_type: "binary".into(),
wrong_type: other.get_type().to_string(),
dst_span: span,
src_span: other.span(),
},
span,
),
}
}
fn index_of_impl(input: &[u8], arg: &Arguments, span: Span) -> Value {
if arg.all {
search_all_index(input, &arg.pattern, arg.end, span)
} else {
let mut iter = input.windows(arg.pattern.len());
if arg.end {
Value::int(
iter.rev()
.position(|sub_bytes| sub_bytes == arg.pattern)
.map(|x| (input.len() - arg.pattern.len() - x) as i64)
.unwrap_or(-1),
span,
)
} else {
Value::int(
iter.position(|sub_bytes| sub_bytes == arg.pattern)
.map(|x| x as i64)
.unwrap_or(-1),
span,
)
}
}
}
fn search_all_index(input: &[u8], pattern: &[u8], from_end: bool, span: Span) -> Value {
let mut result = vec![];
if from_end {
let (mut left, mut right) = (
input.len() as isize - pattern.len() as isize,
input.len() as isize,
);
while left >= 0 {
if &input[left as usize..right as usize] == pattern {
result.push(Value::int(left as i64, span));
left -= pattern.len() as isize;
right -= pattern.len() as isize;
} else {
left -= 1;
right -= 1;
}
}
Value::list(result, span)
} else {
let (mut left, mut right) = (0, pattern.len());
let input_len = input.len();
let pattern_len = pattern.len();
while right <= input_len {
if &input[left..right] == pattern {
result.push(Value::int(left as i64, span));
left += pattern_len;
right += pattern_len;
} else {
left += 1;
right += 1;
}
}
Value::list(result, span)
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_examples() -> nu_test_support::Result {
nu_test_support::test().examples(BytesIndexOf)
}
}