{"product_id":"sed-awk-unix-power-tools-9781565922259","title":"sed \u0026 awk: Unix Power Tools","description":"\u003cp\u003e • Author(s): Dale Dougherty\u003cbr\u003e • Publisher: O'Reilly Media\u003cbr\u003e • Publisher Imprint: O'Reilly Media\u003cbr\u003e • BISAC: Languages - General\u003c\/p\u003e\u003cp\u003e\u003ci\u003esed \u0026amp; awk\u003c\/i\u003e describes two text processing programs that are mainstays of the UNIX programmer's toolbox. \u003ci\u003esed\u003c\/i\u003e is a \"stream editor\" for editing streams of text that might be too large to edit as a single file, or that might be generated on the fly as part of a larger data processing step. The most common operation done with \u003ci\u003esed\u003c\/i\u003e is substitution, replacing one block of text with another. \u003ci\u003eawk\u003c\/i\u003e is a complete programming language. Unlike many conventional languages, \u003ci\u003eawk\u003c\/i\u003e is \"data driven\" -- you specify what kind of data you are interested in and the operations to be performed when that data is found. \u003ci\u003eawk\u003c\/i\u003e does many things for you, including automatically opening and closing data files, reading records, breaking the records up into fields, and counting the records. While \u003ci\u003eawk\u003c\/i\u003e provides the features of most conventional programming languages, it also includes some unconventional features, such as extended regular expression matching and associative arrays. \u003ci\u003esed \u0026amp; awk\u003c\/i\u003e describes both programs in detail and includes a chapter of example \u003ci\u003esed\u003c\/i\u003e and \u003ci\u003eawk\u003c\/i\u003e scripts. This edition covers features of \u003ci\u003esed\u003c\/i\u003e and \u003ci\u003eawk\u003c\/i\u003e that are mandated by the POSIX standard. This most notably affects \u003ci\u003eawk\u003c\/i\u003e, where POSIX standardized a new variable, CONVFMT, and new functions, \u003ci\u003etoupper\u003c\/i\u003e() and \u003ci\u003etolower\u003c\/i\u003e(). The CONVFMT variable specifies the conversion format to use when converting numbers to strings (\u003ci\u003eawk\u003c\/i\u003e used to use OFMT for this purpose). The \u003ci\u003etoupper\u003c\/i\u003e() and \u003ci\u003etolower\u003c\/i\u003e() functions each take a (presumably mixed case) string argument and return a new version of the string with all letters translated to the corresponding case. In addition, this edition covers GNU \u003ci\u003esed\u003c\/i\u003e, newly available since the first edition. It also updates the first edition coverage of Bell Labs \u003ci\u003enawk\u003c\/i\u003e and GNU \u003ci\u003eawk\u003c\/i\u003e (\u003ci\u003egawk\u003c\/i\u003e), covers \u003ci\u003emawk\u003c\/i\u003e, an additional freely available implementation of \u003ci\u003eawk\u003c\/i\u003e, and briefly discusses three commercial versions of \u003ci\u003eawk\u003c\/i\u003e, MKS \u003ci\u003eawk\u003c\/i\u003e, Thompson Automation \u003ci\u003eawk\u003c\/i\u003e (\u003ci\u003etawk\u003c\/i\u003e), and Videosoft (VSAwk).\u003c\/p\u003e","brand":"O'Reilly Media","offers":[{"title":"Paperback","offer_id":45035344855191,"sku":"9781565922259","price":3347.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0666\/3471\/1191\/files\/9781565922259.webp?v=1767262467","url":"https:\/\/atlanticbooks.com\/products\/sed-awk-unix-power-tools-9781565922259","provider":"Atlantic Books","version":"1.0","type":"link"}