{"id":3995,"date":"2015-09-18T11:35:32","date_gmt":"2015-09-18T11:35:32","guid":{"rendered":"http:\/\/blog.bachi.net\/?p=3995"},"modified":"2015-09-18T13:46:17","modified_gmt":"2015-09-18T13:46:17","slug":"awk","status":"publish","type":"post","link":"https:\/\/blog.bachi.net\/?p=3995","title":{"rendered":"awk"},"content":{"rendered":"

awk = A<\/strong>ho, W<\/strong>einberger, and K<\/strong>ernighan<\/p>\n

\r\n$0 = whole line\r\n$1 = first field\r\n$2 = second field\r\n[...]\r\n$NF = last field\r\nFS = field separator, default FS=\\s+\r\nOFS = output field seperator\r\nRS = record (line) separator\r\nORS = output record seperator\r\nNR = number of records (counter from 1 to n)\r\nNF = total number of fields\r\nFILENAME = name of the current input file\r\nFNR = number of records relative to the current input file\r\nmatch()\r\n  -> RSTART = where the pattern starts\r\n  -> RLENGTH = the length of the pattern\r\n<\/pre>\n
Starters<\/h3>\n
Awk – A Tutorial and Introduction – by Bruce Barnett<\/a>
\nAwk Introduction Tutorial \u2013 7 Awk Print Examples<\/a>
\n10 Awk Tips, Tricks and Pitfalls<\/a><\/p>\n
BEGIN and END<\/h3>\n
gawk Manual – Startup and Cleanup Actions<\/a>
\nAWK scripting: 10 BEGIN and END block examples<\/a><\/p>\n
\r\nBEGIN { just once }\r\n{ every record by itself }\r\nEND { just once }\r\n<\/pre>\n
Built-In Variables<\/h3>\n
8 Powerful Awk Built-in Variables \u2013 FS, OFS, RS, ORS, NR, NF, FILENAME, FNR<\/a><\/p>\n
String Functions<\/h3>\n
gawk Manual – String-Manipulation Functions<\/a><\/p>\n
String concatenate<\/h3>\n
awk – concatenate two string variable and assign to a third<\/a>
\ngawk Manual – String Concatenation<\/a><\/p>\n
\r\n$ awk '{b=$1$2; print b}' file\r\n$ awk '{b=$1" "$2; print b}' file\r\n$ awk '{b=$1 FS $2; print b}' file\r\n<\/pre>\n
Regex<\/h3>\n
gawk Manual – Using Dynamic Regexps<\/a>
\ngawk Manual – Using Regular Expression Constants<\/a>
\nPass shell variable as a \/pattern\/ to awk<\/a>
\nHow to use awk variables in regular expressions?<\/a>
\nPassing variable to awk and using that in a regular expression<\/a><\/p>\n
Shell Variables<\/h3>\n
Can we use shell variables in awk?<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
awk = Aho, Weinberger, and Kernighan $0 = whole line $1 = first field $2 = second field […] $NF = last field FS = field separator, default FS=\\s+ OFS = output field seperator RS = record (line) separator ORS = output record seperator NR = number of records (counter from 1 to n) NF […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-3995","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/blog.bachi.net\/index.php?rest_route=\/wp\/v2\/posts\/3995","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.bachi.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.bachi.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.bachi.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.bachi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3995"}],"version-history":[{"count":9,"href":"https:\/\/blog.bachi.net\/index.php?rest_route=\/wp\/v2\/posts\/3995\/revisions"}],"predecessor-version":[{"id":4013,"href":"https:\/\/blog.bachi.net\/index.php?rest_route=\/wp\/v2\/posts\/3995\/revisions\/4013"}],"wp:attachment":[{"href":"https:\/\/blog.bachi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3995"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.bachi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3995"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.bachi.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3995"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}