https://marktaguiad.dev/tags/awk/ Recent content in Awk on marktaguiad.dev Hugo en-us marktaguiad@marktaguiad.dev (Mark Taguiad) marktaguiad@marktaguiad.dev (Mark Taguiad) marktaguiad.dev Wed, 18 Feb 2026 00:00:00 +0000 https://marktaguiad.dev/post/awk-notes/ Wed, 18 Feb 2026 00:00:00 +0000marktaguiad@marktaguiad.dev (Mark Taguiad) https://marktaguiad.dev/post/awk-notes/ <img src="https://marktaguiad.dev/images/linux/ranger-vim-sed-awk-find/awkranger.jpeg" alt="imagen" style="display: block; margin: 0 auto;" loading="lazy" > <h1 id="table-of-contents">Table of Contents</h1> <nav id="TableOfContents"> <ol> <li><a href="#what-is-awk">What is Awk?</a></li> <li><a href="#print">Print</a> <ol> <li><a href="#lines">Lines</a></li> <li><a href="#match-and-print">Match and print</a></li> <li><a href="#line-numbers">Line numbers</a></li> </ol> </li> <li><a href="#fields-and-columns">Fields and Columns</a> <ol> <li><a href="#print-column">Print column</a></li> <li><a href="#field-separator">Field separator</a></li> <li><a href="#changing-the-output-separator">Changing the output separator</a></li> <li><a href="#conditions---patterns">Conditions - patterns</a></li> </ol> </li> <li><a href="#calculations-and-fields">Calculations and Fields</a> <ol> <li><a href="#basic-calculation">Basic Calculation</a></li> <li><a href="#built-n-variables">Built-n Variables</a> <ol> <li><a href="#nr---record-number">NR - Record Number</a></li> <li><a href="#nf--number-of-fields">NF – Number of Fields</a></li> <li><a href="#nf--last-field">$NF – Last Field</a></li> <li><a href="#fs--input-field-separator">FS – Input Field Separator</a></li> <li><a href="#ofs--output-field-separator">OFS – Output Field Separator</a></li> </ol> </li> <li><a href="#changing-fields">Changing Fields</a></li> <li><a href="#filtering-rows">Filtering Rows</a></li> <li><a href="#multiple-conditions">Multiple Conditions</a></li> </ol> </li> <li><a href="#strings-and-texts">Strings and Texts</a> <ol> <li><a href="#string-functions">String Functions</a> <ol> <li><a href="#length0">length($0)</a></li> <li><a href="#tolowerstring">tolower(string)</a></li> <li><a href="#toupperstring">toupper(string)</a></li> <li><a href="#substrstring-start-length">substr(string, start, length)</a></li> <li><a href="#indexstring-search">index(string, search)</a></li> <li><a href="#splitstring-array-sep">split(string, array, sep)</a></li> </ol> </li> <li><a href="#find-and-replace">Find and Replace</a></li> </ol> </li> <li><a href="#control-flow">Control Flow</a> <ol> <li><a href="#ifelse">if/else</a></li> <li><a href="#loops">loops</a></li> </ol> </li> <li><a href="#arrays">Arrays</a> <ol> <li><a href="#counting-occurrences">Counting Occurrences</a></li> <li><a href="#summing-by-category">Summing by Category</a></li> </ol> </li> <li><a href="#advance-functions">Advance Functions</a> <ol> <li><a href="#custom-functions">Custom Functions</a></li> <li><a href="#multi-file-processing">Multi-file Processing</a></li> <li><a href="#begin-and-end-blocks">BEGIN and END Blocks</a></li> <li><a href="#formatting-output">Formatting Output</a> <ol> <li><a href="#align-columns">Align Columns</a></li> <li><a href="#format-numbers">Format Numbers</a></li> <li><a href="#combine-strings-and-numbers">Combine Strings and Numbers</a></li> </ol> </li> </ol> </li> <li><a href="#real-world-use-cases">Real-World Use Cases</a> <ol> <li><a href="#extract-columns-from-logs">Extract Columns from Logs</a></li> <li><a href="#count-http-status-codes">Count HTTP Status Codes</a></li> <li><a href="#csv-report">CSV Report</a></li> <li><a href="#find-top-user-by-usage">Find Top User by Usage</a></li> </ol> </li> </ol> </nav> <h3 id="what-is-awk">What is Awk?</h3> <p>AWK is a pattern–action text processing language great for logs, CSVs, reports, and automation.</p>