add more bytes cmd (#5989)

crates/nu-command/src/bytes/index_of.rs

@@ -0,0 +1,177 @@
+use super::{operate, BytesArgument};
+use nu_engine::CallExt;
+use nu_protocol::ast::{Call, CellPath};
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+};
+
+struct Arguments {
+    pattern: Vec<u8>,
+    end: bool,
+    all: bool,
+    column_paths: Option<Vec<CellPath>>,
+}
+
+impl BytesArgument for Arguments {
+    fn take_column_paths(&mut self) -> Option<Vec<CellPath>> {
+        self.column_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")
+            .required(
+                "pattern",
+                SyntaxShape::Binary,
+                "the pattern to find index of",
+            )
+            .rest(
+                "rest",
+                SyntaxShape::CellPath,
+                "optionally returns index of pattern in string by column paths",
+            )
+            .switch("all", "returns all matched index", Some('a'))
+            .switch("end", "search from the end of the binary", Some('e'))
+            .category(Category::Bytes)
+    }
+
+    fn usage(&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", "index"]
+    }
+
+    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 column_paths: Vec<CellPath> = call.rest(engine_state, stack, 1)?;
+        let column_paths = if column_paths.is_empty() {
+            None
+        } else {
+            Some(column_paths)
+        };
+        let arg = Arguments {
+            pattern,
+            end: call.has_flag("end"),
+            all: call.has_flag("all"),
+            column_paths,
+        };
+        operate(index_of, arg, input, call.head, engine_state.ctrlc.clone())
+    }
+
+    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 -e 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 -a 0x[33 44]",
+                result: Some(Value::List {
+                    vals: vec![Value::test_int(0), Value::test_int(5), Value::test_int(7)],
+                    span: Span::test_data(),
+                }),
+            },
+            Example {
+                description: "Returns index of pattern for specific column",
+                example: r#" [[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::List {
+                    vals: vec![Value::Record {
+                        cols: vec!["ColA".to_string(), "ColB".to_string(), "ColC".to_string()],
+                        vals: vec![
+                            Value::test_int(0),
+                            Value::Binary {
+                                val: vec![0x14, 0x15, 0x16],
+                                span: Span::test_data(),
+                            },
+                            Value::test_int(-1),
+                        ],
+                        span: Span::test_data(),
+                    }],
+                    span: Span::test_data(),
+                }),
+            },
+        ]
+    }
+}
+
+fn index_of(input: &[u8], arg: &Arguments, span: Span) -> Value {
+    // currently, `--all` flag doesn't support finding from end.
+    if arg.all {
+        let mut result = vec![];
+        // doing find stuff.
+        let (mut left, mut right) = (0, arg.pattern.len());
+        let input_len = input.len();
+        let pattern_len = arg.pattern.len();
+        while right <= input_len {
+            if input[left..right] == arg.pattern {
+                result.push(Value::Int {
+                    val: left as i64,
+                    span,
+                });
+                left += pattern_len;
+                right += pattern_len;
+            } else {
+                left += 1;
+                right += 1;
+            }
+        }
+        Value::List { vals: result, span }
+    } else {
+        let mut iter = input.windows(arg.pattern.len());
+
+        if arg.end {
+            Value::Int {
+                val: 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 {
+                val: iter
+                    .position(|sub_bytes| sub_bytes == arg.pattern)
+                    .map(|x| x as i64)
+                    .unwrap_or(-1),
+                span,
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(BytesIndexOf {})
+    }
+}