{"id":353621,"date":"2024-09-27T05:34:59","date_gmt":"2024-09-27T05:34:59","guid":{"rendered":"https:\/\/www.ninjaone.com\/script-hub\/protokolle-uberwachen-unter-linux\/"},"modified":"2024-10-29T08:27:31","modified_gmt":"2024-10-29T08:27:31","slug":"protokolldateien-mit-einem-bash-skript-ueberwachen","status":"publish","type":"script_hub","link":"https:\/\/www.ninjaone.com\/de\/script-hub\/protokolldateien-mit-einem-bash-skript-ueberwachen\/","title":{"rendered":"\u00dcberwachung von Protokolldateien und Erkennung bestimmter Texte unter Linux mithilfe eines Bash-Skripts"},"content":{"rendered":"

F\u00fcr IT-Experten ist es unerl\u00e4sslich zu wissen, wie man Protokolldateien mit einem Bash-Skript \u00fcberwachen kann und wie sich bestimmte Textmuster erkennen lassen, insbesondere im Zusammenhang mit der Systemverwaltung und der Cyber-Sicherheit<\/a>. Automatisierte Skripte, die auf bestimmte Textzeichenfolgen in Dateien aufmerksam machen k\u00f6nnen, sind unsch\u00e4tzbare Tools im Toolkit eines IT-Experten.<\/p>\n

Das mitgelieferte Skript erf\u00fcllt diese Aufgabe auf effektive Weise und bietet eine zuverl\u00e4ssige L\u00f6sung f\u00fcr das\u00a0Monitoring von Protokollen und die Benachrichtigung beim Auftreten bestimmter Textzeichenfolgen<\/strong>. In diesem Blogbeitrag werden die Funktionen des Skripts n\u00e4her erl\u00e4utert, seine praktischen Anwendungen untersucht und Best Practices f\u00fcr seine Verwendung er\u00f6rtert.<\/p>\n

Verst\u00e4ndnis vom Skript und dessen Bedeutung<\/h2>\n

In IT-Umgebungen werden kontinuierlich Protokolldateien von verschiedenen Systemen, Anwendungen und Prozessen erzeugt. Diese Protokolle enthalten essenzielle Informationen \u00fcber den Betrieb des Systems, Fehler, Sicherheitsereignisse und Benutzeraktivit\u00e4ten. Das manuelle Monitoring dieser Dateien auf kritische Ereignisse oder Textzeichenfolgen ist jedoch unpraktisch und anf\u00e4llig f\u00fcr menschliches Versagen<\/a>. An dieser Stelle wird die Automatisierung durch Skripte unerl\u00e4sslich.<\/p>\n

Das mitgelieferte Skript ist so konzipiert, dass es nach einem bestimmten Text in einer Protokolldatei sucht und eine Warnmeldung erzeugt, wenn dieser Text gefunden wird. Dieses Skript ist besonders n\u00fctzlich f\u00fcr Managed Service Provider (MSPs)<\/a> und IT-Administratoren, die Protokolle auf Sicherheitsvorf\u00e4lle, Anwendungsfehler oder andere wichtige Ereignisse \u00fcberwachen m\u00fcssen, die sofortige Aufmerksamkeit erfordern k\u00f6nnten.<\/p>\n

Das Skript:<\/h2>\n
#!\/usr\/bin\/env bash\r\n\r\n# Description: Alert when the specified Text is found in a text file.\r\n#\r\n# Release Notes: Initial Release\r\n#   By using this script, you indicate your acceptance of the following legal terms as well as our Terms of Use at https:\/\/www.ninjaone.com\/terms-of-use.\r\n#   Ownership Rights: NinjaOne owns and will continue to own all right, title, and interest in and to the script (including the copyright). NinjaOne is giving you a limited license to use the script in accordance with these legal terms. \r\n#   Use Limitation: You may only use the script for your legitimate personal or internal business purposes, and you may not share the script with another party. \r\n#   Republication Prohibition: Under no circumstances are you permitted to re-publish the script in any script library or website belonging to or under the control of any other software provider. \r\n#   Warranty Disclaimer: The script is provided \u201cas is\u201d and \u201cas available\u201d, without warranty of any kind. NinjaOne makes no promise or guarantee that the script will be free from defects or that it will meet your specific needs or expectations. \r\n#   Assumption of Risk: Your use of the script is at your own risk. You acknowledge that there are certain inherent risks in using the script, and you understand and assume each of those risks. \r\n#   Waiver and Release: You will not hold NinjaOne responsible for any adverse or unintended consequences resulting from your use of the script, and you waive any legal or equitable rights or remedies you may have against NinjaOne relating to your use of the script. \r\n#   EULA: If you are a NinjaOne customer, your use of the script is subject to the End User License Agreement applicable to you (EULA).\r\n#\r\n# Text to trigger on: [Alert]\r\n#\r\n# Below are all the valid parameters for this script.\r\n# Preset Parameter: --file \"\/opt\/MyLogFile.log\" --text batman\r\n#   Alerts when the text \"batman\" is found in the file \/opt\/MyLogFile.log\r\n#    This is Case Sensitive\r\n#     Example where it will alert: \"I am batman!\"\r\n#     Example where it will alert: \"Iambatman!\"\r\n#     Example where it will not alert: \"IamBatman!\"\r\n#     Example where it will not alert: \"I am Batman!\"\r\n#\r\n# Preset Parameter: --file \"\/opt\/MyLogFile.log\" --text Batman --caseInsensitive true\r\n#   Alerts when the text \"Batman\" is found in the file \/opt\/MyLogFile.log, but is case insensitive\r\n#    This is Case Insensitive\r\n#     Example where it will alert: \"I am batman!\"\r\n#     Example where it will alert: \"Iambatman!\"\r\n#\r\n# Preset Parameter: --file \"\/opt\/MyLogFile.log\" --text Batman --wholeWord true\r\n#   Alerts when the text \"Batman\" is found in the file \/opt\/MyLogFile.log, but only if it is a word in a sentence.\r\n#    This is Case Sensitive\r\n#     Example where it will alert: \"I am Batman!\"\r\n#     Example where it will not alert: \"IamBatman!\"\r\n#\r\n\r\n# Determines whether or not help text is necessary and routes the output to stderr\r\ndie() {\r\n    local _ret=\"${2:-1}\"\r\n    test \"${_PRINT_HELP:-no}\" = yes && print_help >&2\r\n    echo \"$1\" >&2\r\n    exit \"${_ret}\"\r\n}\r\n\r\n# Function that evaluates whether a value passed to it begins by a character\r\n# that is a short option of an argument the script knows about.\r\n# This is required in order to support getopts-like short options grouping.\r\nbegins_with_short_option() {\r\n    local first_option all_short_options='ftiwh'\r\n    first_option=\"${1:0:1}\"\r\n    test \"$all_short_options\" = \"${all_short_options\/$first_option\/}\" && return 1 || return 0\r\n}\r\n\r\n# THE DEFAULTS INITIALIZATION - OPTIONALS\r\n_arg_file=\r\n_arg_text=\r\n_arg_caseInsensitive=\"false\"\r\n_arg_wholeWord=\"false\"\r\n\r\n# Help text function for when invalid input is encountered\r\nprint_help() {\r\n    printf '%s\\n' \"Alert when the specified Text is found in a text file.\"\r\n    printf 'Usage: %s [-f|--file [path to file]] [-t|--text [text to search]] [-i|--caseInsensitive <true|false>] [-w|--wholeWord <true|false>] [-h|--help]\\n' \"$0\"\r\n    printf '\\t%s\\n' \"-f, --file: path to a log file\"\r\n    printf '\\t%s\\n' \"-t, --text: text to alert when found\"\r\n    printf '\\t%s\\n' \"-i, --caseInsensitive: search text with case insensitivity (default: false)\"\r\n    printf '\\t%s\\n' \"-w, --wholeWord: search for text as a whole word (default: false)\"\r\n    printf '\\t%s\\n' \"-h, --help: Prints help\"\r\n}\r\n\r\n# Grabbing the parameters and parsing through them.\r\nparse_commandLine() {\r\n    while test $# -gt 0; do\r\n        _key=\"$1\"\r\n        case \"$_key\" in\r\n        -f | --file)\r\n            test $# -lt 2 && die \"Missing value for the optional argument '$_key'.\" 1\r\n            _arg_file=\"$2\"\r\n            shift\r\n            ;;\r\n        --file=*)\r\n            _arg_file=\"${_key##--file=}\"\r\n            ;;\r\n        -f*)\r\n            _arg_file=\"${_key##-f}\"\r\n            ;;\r\n        -t | --text)\r\n            test $# -lt 2 && die \"Missing value for the optional argument '$_key'.\" 1\r\n            _arg_text=\"$2\"\r\n            shift\r\n            ;;\r\n        --text=*)\r\n            _arg_text=\"${_key##--text=}\"\r\n            ;;\r\n        -t*)\r\n            _arg_text=\"${_key##-t}\"\r\n            ;;\r\n        -i | --caseInsensitive)\r\n            test $# -lt 2 && die \"Missing value for the optional argument '$_key'.\" 1\r\n            _arg_caseInsensitive=\"$2\"\r\n            shift\r\n            ;;\r\n        --caseInsensitive=*)\r\n            _arg_caseInsensitive=\"${_key##--caseInsensitive=}\"\r\n            ;;\r\n        -i*)\r\n            _arg_caseInsensitive=\"${_key##-i}\"\r\n            ;;\r\n        -w | --wholeWord)\r\n            test $# -lt 2 && die \"Missing value for the optional argument '$_key'.\" 1\r\n            _arg_wholeWord=\"$2\"\r\n            shift\r\n            ;;\r\n        --wholeWord=*)\r\n            _arg_wholeWord=\"${_key##--wholeWord=}\"\r\n            ;;\r\n        -w*)\r\n            _arg_wholeWord=\"${_key##-w}\"\r\n            ;;\r\n        -h | --help)\r\n            print_help\r\n            exit 0\r\n            ;;\r\n        -h*)\r\n            print_help\r\n            exit 0\r\n            ;;\r\n        *)\r\n            _PRINT_HELP=yes die \"FATAL ERROR: Got an unexpected argument '$1'\" 1\r\n            ;;\r\n        esac\r\n        shift\r\n    done\r\n}\r\n\r\nparse_commandLine \"$@\"\r\n\r\ntext=$_arg_text\r\nfile=$_arg_file\r\ncaseInsensitive=$_arg_caseInsensitive\r\nwholeWord=$_arg_wholeWord\r\n\r\n# Check if Script Variables where used and overwrite command line parameters\r\nif [[ -n \"${textToMatch}\" ]]; then\r\n    text=$textToMatch\r\nfi\r\nif [[ -n \"${textFile}\" ]]; then\r\n    file=$textFile\r\nfi\r\nif [[ -n \"${matchWholeWord}\" ]]; then\r\n    wholeWord=$matchWholeWord\r\nfi\r\nif [[ -n \"${insensitiveToCase}\" ]]; then\r\n    caseInsensitive=$insensitiveToCase\r\nfi\r\n\r\n# Check if text is not an empty string\r\nif [[ -z \"${text}\" ]]; then\r\n    echo \"[Error] Text not specified\"\r\n    exit 2\r\nfi\r\n\r\n# Check if text is not an empty string\r\nif [[ -z \"${file}\" ]]; then\r\n    echo \"[Error] File not specified\"\r\n    exit 2\r\nfi\r\n\r\n# Does file exit and is readable\r\nif [ -f \"${file}\" ]; then\r\n    echo \"[Info] File \\\"${file}\\\" exists\"\r\n    if [ -r \"${file}\" ]; then\r\n        echo \"[Info] File \\\"${file}\\\" is readable\"\r\n    else\r\n        echo \"[Error] File \\\"${file}\\\" is not readable\"\r\n        exit 2\r\n    fi\r\nelse\r\n    echo \"[Error] File \\\"${file}\\\" does not exists\"\r\n    exit 2\r\nfi\r\n\r\n# Detect\r\ncount=0\r\nif [[ \"${wholeWord}\" == \"true\" ]]; then\r\n    if [[ \"${caseInsensitive}\" == \"true\" ]]; then\r\n        count=$(grep -c -i -n -w \"$text\" \"$file\")\r\n    else\r\n        count=$(grep -c -n -w \"$text\" \"$file\")\r\n    fi\r\nelse\r\n    if [[ \"${caseInsensitive}\" == \"true\" ]]; then\r\n        count=$(grep -c -i -n -e \"$text\" \"$file\")\r\n    else\r\n        count=$(grep -c -n -e \"$text\" \"$file\")\r\n    fi\r\nfi\r\n\r\n# Alert\r\nif ((count > 0)); then\r\n    echo \"[Alert] Found text in file\"\r\n    exit 1\r\nelse\r\n    echo \"[Info] Not found text in file\"\r\n    exit 0\r\nfi<\/pre>\n
 <\/p>\n\n
<\/h2>
<\/p><\/div>
<\/a><\/div><\/div>\n
Detaillierte Aufschl\u00fcsselung des Skripts<\/h2>\n
Schauen wir uns genauer an, wie dieses Skript funktioniert:<\/p>\n
1.\u00a0Parameter<\/strong>\u00a0-Parsen:\u00a0<\/strong><\/p>\n