{
  "name": "grep",
  "section": 1,
  "title": "pattern matching utility",
  "synopsis": [
    "grep [-E|-F] [-i] [-v] [-n] [-c] [-l] [-q] [-s] [-H|-h] [-e pat] ... [-f file] ... [pattern] [file...]"
  ],
  "description": "Searches input or files for lines matching a pattern. Uses JavaScript RegExp unless -F (fixed string). Not bit-identical to GNU grep.",
  "options": [
    {
      "flag": "-E",
      "meaning": "Extended regex (accepted; patterns use JS RegExp)"
    },
    {
      "flag": "-F",
      "meaning": "Fixed string match"
    },
    {
      "flag": "-i",
      "meaning": "Ignore case"
    },
    {
      "flag": "-v",
      "meaning": "Invert match"
    },
    {
      "flag": "-n",
      "meaning": "Prefix lines with line number"
    },
    {
      "flag": "-c",
      "meaning": "Count matching lines only"
    },
    {
      "flag": "-l",
      "meaning": "List files with matches"
    },
    {
      "flag": "-q",
      "meaning": "Quiet (exit status only)"
    },
    {
      "flag": "-s",
      "meaning": "Suppress error messages"
    },
    {
      "flag": "-H / -h",
      "meaning": "Force / suppress filename prefix"
    },
    {
      "flag": "-e pat",
      "meaning": "Specify pattern"
    },
    {
      "flag": "-f file",
      "meaning": "Read patterns from file"
    }
  ],
  "keywords": [
    "grep",
    "search",
    "regex",
    "pattern",
    "filter"
  ],
  "seeAlso": [
    {
      "name": "sed",
      "section": 1
    },
    {
      "name": "awk",
      "section": 1
    }
  ],
  "bareOsNotes": "UTF-16 strings and JS regex differ from strict POSIX/GNU.",
  "examples": [
    {
      "caption": "recursive feel (grep each file)",
      "code": "grep -n error *.log"
    },
    {
      "caption": "case insensitive",
      "code": "grep -i todo NOTES.md"
    },
    {
      "caption": "invert (lines without)",
      "code": "grep -v '^#' config"
    },
    {
      "caption": "fixed string (no regex)",
      "code": "grep -F \"v1.0\" CHANGES"
    },
    {
      "caption": "count matches",
      "code": "grep -c FAIL build.log"
    },
    {
      "caption": "only filenames",
      "code": "grep -l main *.js"
    },
    {
      "caption": "multiple patterns",
      "code": "grep -e foo -e bar file.txt"
    }
  ]
}