igawk

gawk [options] [-f program_file | 'program_text'] [file ...]

The program can be supplied either as a string on the command line ('program_text') or by reading from a file (-f program_file). If no files are specified, gawk reads from standard input.

-F fs
    Sets fs as the input field separator. The default is whitespace.

-v var=value
    Assigns a value to a variable before the AWK program begins execution.

-f program-file
    Reads the AWK program source from the specified program-file.

-e program-text
    Specifies an AWK program directly on the command line. Useful for multiple program fragments.

--posix
    Enables strict POSIX compatibility for gawk, affecting behavior like field parsing and string conversions.

--version
    Prints gawk's version and copyright information to standard output.

--help
    Prints a concise usage summary for gawk to standard output.

The command igawk is not a standard Linux command. It is almost certainly a common typographical error for gawk, which is the GNU implementation of the awk programming language.

gawk is a powerful text processing tool designed for pattern scanning and processing. It reads input line by line, attempts to match each line against a series of patterns, and performs specified actions for lines that match. It functions as a full-fledged programming language, supporting variables, arithmetic operators, string functions, control flow statements (if/else, loops), and user-defined functions.

Common uses for gawk include data extraction and reformatting, generating reports, processing log files, and performing complex text manipulations. Its ability to process data based on fields and records makes it exceptionally versatile for structured and semi-structured text data.

The command igawk itself does not exist as a standard utility in Linux distributions. If encountered, it is almost certainly a typo for gawk, which is the GNU implementation of awk. Users should ensure they are invoking gawk or awk directly. The awk language, while powerful, has a learning curve due to its unique syntax and processing model.

To print the first and third fields of a comma-separated file:
gawk -F',' '{print $1, $3}' mydata.csv

To count lines matching a pattern:
gawk '/pattern/{count++} END{print count}' logfile.txt

gawk supports variables, arrays (associative), built-in string and arithmetic functions, and control flow statements (if, else, while, for, break, continue). It also allows defining custom functions and including external libraries.

The original awk language was developed at Bell Labs in the 1970s by Alfred Aho, Peter Weinberger, and Brian Kernighan (the 'AWK' acronym comes from their initials). It was designed for text processing and data manipulation. gawk, the GNU project's implementation of awk, was created to provide a free and open-source version that extends and enhances the original awk functionality, adhering to the POSIX standard while adding many powerful features.

awk(1), sed(1), grep(1), cut(1), perl(1)