awk study(11)

1.7 Other Features of awk

      The awk language provides a numbers of predefine or build-in, variables that your programs  can use to get information from awk, There are other variables your programs can set as well to control how awk processes your data.

    In addition, awk provides a numbers of  build-in functions to do common computation, gawk proveds build-in functions for working with timestamps, bit manipulation, and for runtime string translation.

     As we develop our awk presentation of awk language, we introduce most of the variables and many of the functions, They are defined systematically in Build-in variables and Build-in.

1.8 When to use awk

     Now that you have seen some of what awk can do, you might wonder how awk could be useful for you. By using utility programs, advanced patterns, field separators, arithmetic statements and other selection criteria, you can produce much more complex output,the awk language is very useful for producing report from large amounts of raw data, such as summarizing information from the output of other utility programs like ls.

      Programs written by awk usually are smaller than they would be in other languages, this make awk programs easy to compose and use, often , awk programs can quickly  composed at your terminal, used once and thrown away. Because awk programs are interpreted , you can avoid the compilation  part of  the typical  edit-compile-test-debug cycle of software development.