1# 2# CDDL HEADER START 3# 4# The contents of this file are subject to the terms of the 5# Common Development and Distribution License, Version 1.0 only 6# (the "License"). You may not use this file except in compliance 7# with the License. 8# 9# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10# or http://www.opensolaris.org/os/licensing. 11# See the License for the specific language governing permissions 12# and limitations under the License. 13# 14# When distributing Covered Code, include this CDDL HEADER in each 15# file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16# If applicable, add the following below this CDDL HEADER, with the 17# fields enclosed by brackets "[]" replaced with your own identifying 18# information: Portions Copyright [yyyy] [name of copyright owner] 19# 20# CDDL HEADER END 21# 22CHANGES as of July 12: 23 241. \ddd allowed in regular expressions. 25 262. exit <expression> causes the expression to 27to be the status return upon completion. 28 293. a new builtin called "getline" causes the next 30input line to be read immediately. Fields, NR, etc., 31are all set, but you are left at exactly the same place 32in the awk program. Getline returns 0 for end of file; 331 for a normal record. 34 35 36CHANGES SINCE MEMO: 37Update to TM of Sept 1, 1978: 38 391. A new form of for loop 40 for (i in array) 41 statement 42is now available. It provides a way to walk 43along the members of an array, most usefully 44for associative arrays with non-numeric subscripts. 45Elements are accessed in an unpredictable order, 46so don't count on anything. 47Futhermore, havoc ensues if elements are created 48during this operation, or if the index variable 49is fiddled. 50 512. index(s1, s2) returns the position in s1 52where s2 first occurs, or 0 if it doesn't. 53 543. Multi-line records are now supported more 55conveniently. If the record separator is null 56 RS = "" 57then a blank line terminates a record, and newline 58is a default field separator, along with 59blank and tab. 60 614. The syntax of split has been changed. 62 n = split(str, arrayname, sep) 63splits the string str into the array using 64the separator sep (a single character). 65If no sep field is given, FS is used instead. 66The elements are array[1] ... array[n]; n 67is the function value. 68 695. some minor bugs have been fixed. 70 71IMPLEMENTATION NOTES: 72 73Things to watch out for when trying to make awk: 74 751. The yacc -d business creates a new file y.tab.h 76with the yacc #defines in it. this is compared to 77awk.h on each successive compile, and major recompilation 78is done only if the files differ. (This permits editing 79the grammar file without causing everything in sight 80to be recompiled, so long as the definitions don't 81change.) 82 832. The program proc.c is compiled into proc, which 84is used to create proctab.c. proctab.c is the 85table of function pointers used by run to actually 86execute things. Don't try to load proc.c with the 87other .c files; it also contains a "main()". 88 893. Awk uses structure assignment. Be sure your 90version of the C compiler has it. 91 924. The loader flag -lm is used to fetch the standard 93math library on the Research system. It is more likely 94that you will want to use -lS on yours. 95run.c also includes "math.h", which contains sensible 96definitions for log(), sqrt(), etc. If you don't have this 97include file, comment the line out, and all will be well 98anyway. 99 1005. The basic sequence of events (in case make doesn't 101seem to do the job) is 102 yacc -d awk.g.y 103 cc -O -c y.tab.c 104 mv y.tab.o awk.g.o 105 lex awk.lx.l 106 cc -O -c lex.yy.c 107 mv lex.yy.o awk.lx.o 108 cc -O -c b.c 109 cc -O -c main.c 110 e - <tokenscript 111 cc -O -c token.c 112 cc -O -c tran.c 113 cc -O -c lib.c 114 cc -O -c run.c 115 cc -O -c parse.c 116 cc -O -c proc.c 117 cc -o proc proc.c token.o 118 proc >proctab.c 119 cc -O -c proctab.c 120 cc -i -O awk.g.o awk.lx.o b.o main.o token.o tran.o lib.o run.o parse.o proctab.o -lm 121