What is the difference between sed and awk

Question

What is the difference between awk and sed   What kind of application are best use cases for sed and awk tools

User · Answer

Both tools are meant to work with text and there are tasks both tools can be used for.

For me the rule to separate them is: Use sed to automate tasks you would do otherwise in a text editor manually. That's why it is called stream editor. (You can use the same commands to edit text in vim). Use awk if you want to analyze text, meaning counting fields, calculate totals, extract and reorganize structures etc.

Also you should not forget about grep. Use grep if you only want to search/extract something in a text (file)

User · Answer

sed is a stream editor  It works with streams of characters on a per-line basis  It has a primitive programming language that includes goto-style loops and simple conditionals  in addition to pattern matching and address matching   There are essentially only two  variables   pattern space and hold space  Readability of scripts can be difficult  Mathematical operations are extraordinarily awkward at best   There are various versions of sed with different levels of support for command line options and language features   awk is oriented toward delimited fields on a per-line basis  It has much more robust programming constructs including if else  while  do while and for  C-style and array iteration   There is complete support for variables and single-dimension associative arrays plus  IMO  kludgey multi-dimension arrays  Mathematical operations resemble those in C  It has printf and functions  The  K  in  AWK  stands for  Kernighan  as in  Kernighan and Ritchie  of the book  C Programming Language  fame  not to forget Aho and Weinberger   One could conceivably write a detector of academic plagiarism using awk   GNU awk  gawk  has numerous extensions  including true multidimensional arrays in the latest version  There are other variations of awk including mawk and nawk   Both programs use regular expressions for selecting and processing text   I would tend to use sed where there are patterns in the text  For example  you could replace all the negative numbers in some text that are in the form  minus-sign followed by a sequence of digits   e g   -231 45   with the  accountant s brackets  form  e g    231 45    using this  which has room for improvement    sed  s -   0-9         1  g  inputfile   I would use awk when the text looks more like rows and columns or  as awk refers to them  records  and  fields   If I was going to do a similar operation as above  but only on the third field in a simple comma delimited file I might do something like   awk -F   BEGIN  OFS         gsub  -  0-9           substr  3  2        3   print   inputfile   Of course those are just very simple examples that don t illustrate the full range of capabilities that each has to offer

User · Answer

1  What is the difference between awk and sed    Both are tools that transform text  BUT awk can do more things besides just manipulating text  Its a programming language by itself with most of the things you learn in programming  like arrays  loops  if else flow control etc  You can  program  in sed as well  but you won t want to maintain the code written in it   2  What kind of application are best use cases for sed and awk tools    Conclusion  Use sed for very simple text parsing  Anything beyond that  awk is better  In fact  you can ditch sed altogether and just use awk  Since their functions overlap and awk can do more  just use awk  You will reduce your learning curve as well

[sed] What is the difference between sed and awk?

Examples related to sed

Examples related to awk