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# 22#ident "%Z%%M% %I% %E% SMI" 23CHANGES as of July 12: 24 251. \ddd allowed in regular expressions. 26 272. exit <expression> causes the expression to 28to be the status return upon completion. 29 303. a new builtin called "getline" causes the next 31input line to be read immediately. Fields, NR, etc., 32are all set, but you are left at exactly the same place 33in the awk program. Getline returns 0 for end of file; 341 for a normal record. 35 36 37CHANGES SINCE MEMO: 38Update to TM of Sept 1, 1978: 39 401. A new form of for loop 41 for (i in array) 42 statement 43is now available. It provides a way to walk 44along the members of an array, most usefully 45for associative arrays with non-numeric subscripts. 46Elements are accessed in an unpredictable order, 47so don't count on anything. 48Futhermore, havoc ensues if elements are created 49during this operation, or if the index variable 50is fiddled. 51 522. index(s1, s2) returns the position in s1 53where s2 first occurs, or 0 if it doesn't. 54 553. Multi-line records are now supported more 56conveniently. If the record separator is null 57 RS = "" 58then a blank line terminates a record, and newline 59is a default field separator, along with 60blank and tab. 61 624. The syntax of split has been changed. 63 n = split(str, arrayname, sep) 64splits the string str into the array using 65the separator sep (a single character). 66If no sep field is given, FS is used instead. 67The elements are array[1] ... array[n]; n 68is the function value. 69 705. some minor bugs have been fixed. 71 72IMPLEMENTATION NOTES: 73 74Things to watch out for when trying to make awk: 75 761. The yacc -d business creates a new file y.tab.h 77with the yacc #defines in it. this is compared to 78awk.h on each successive compile, and major recompilation 79is done only if the files differ. (This permits editing 80the grammar file without causing everything in sight 81to be recompiled, so long as the definitions don't 82change.) 83 842. The program proc.c is compiled into proc, which 85is used to create proctab.c. proctab.c is the 86table of function pointers used by run to actually 87execute things. Don't try to load proc.c with the 88other .c files; it also contains a "main()". 89 903. Awk uses structure assignment. Be sure your 91version of the C compiler has it. 92 934. The loader flag -lm is used to fetch the standard 94math library on the Research system. It is more likely 95that you will want to use -lS on yours. 96run.c also includes "math.h", which contains sensible 97definitions for log(), sqrt(), etc. If you don't have this 98include file, comment the line out, and all will be well 99anyway. 100 1015. The basic sequence of events (in case make doesn't 102seem to do the job) is 103 yacc -d awk.g.y 104 cc -O -c y.tab.c 105 mv y.tab.o awk.g.o 106 lex awk.lx.l 107 cc -O -c lex.yy.c 108 mv lex.yy.o awk.lx.o 109 cc -O -c b.c 110 cc -O -c main.c 111 e - <tokenscript 112 cc -O -c token.c 113 cc -O -c tran.c 114 cc -O -c lib.c 115 cc -O -c run.c 116 cc -O -c parse.c 117 cc -O -c proc.c 118 cc -o proc proc.c token.o 119 proc >proctab.c 120 cc -O -c proctab.c 121 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 122