Zabbix

/*

** Copyright (C) 2001-2025 Zabbix SIA

**

** This program is free software: you can redistribute it and/or modify it under the terms of

** the GNU Affero General Public License as published by the Free Software Foundation, version 3.

**

** This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;

** without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

** See the GNU Affero General Public License for more details.

**

** You should have received a copy of the GNU Affero General Public License along with this program.

** If not, see <https://www.gnu.org/licenses/>.

**/

​

package zbxregexp

​

import (

    "bytes"

    "regexp"

)

​

func ExecuteRegex(line []byte, rx *regexp.Regexp, output []byte) (result string, match bool) {

    matches := rx.FindSubmatchIndex(line)

    if len(matches) == 0 {

        return "", false

    }

    if len(output) == 0 {

        return string(line), true

    }

​

    buf := &bytes.Buffer{}

    for len(output) > 0 {

        pos := bytes.Index(output, []byte{'\\'})

        if pos == -1 || pos == len(output)-1 {

            break

        }

        _, _ = buf.Write(output[:pos])

        switch output[pos+1] {

        case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':

            i := output[pos+1] - '0'

            if len(matches) >= int(i)*2+2 {

                if matches[i*2] != -1 {

                    _, _ = buf.Write(line[matches[i*2]:matches[i*2+1]])

                }

            }

            pos++

        case '@':

            _, _ = buf.Write(line[matches[0]:matches[1]])

            pos++

        case '\\':

            _ = buf.WriteByte('\\')

            pos++

        default:

            _ = buf.WriteByte('\\')

        }

        output = output[pos+1:]

    }

    _, _ = buf.Write(output)

    return buf.String(), true

}