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/*
* Perform the basic line parsing of input performed by awk.
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
%%{
machine awkemu;
action start_word {
ws[nwords] = fpc;
}
action end_word {
we[nwords++] = fpc;
}
action start_line {
nwords = 0;
ls = fpc;
}
action end_line {
printf("endline(%i): ", nwords );
fwrite( ls, 1, p - ls, stdout );
printf("\n");
for ( i = 0; i < nwords; i++ ) {
printf(" word: ");
fwrite( ws[i], 1, we[i] - ws[i], stdout );
printf("\n");
}
}
# Words in a line.
word = ^[ \t\n]+;
# The whitespace separating words in a line.
whitespace = [ \t];
# The components in a line to break up. Either a word or a single char of
# whitespace. On the word capture characters.
blineElements = word >start_word %end_word | whitespace;
# Star the break line elements. Just be careful to decrement the leaving
# priority as we don't want multiple character identifiers to be treated as
# multiple single char identifiers.
line = ( blineElements** '\n' ) >start_line @end_line;
# Any number of lines.
main := line*;
}%%
%% write data noerror nofinal;
#define MAXWORDS 256
#define BUFSIZE 4096
char buf[BUFSIZE];
int main()
{
int i, nwords = 0;
char *ls = 0;
char *ws[MAXWORDS];
char *we[MAXWORDS];
int cs;
int have = 0;
%% write init;
while ( 1 ) {
char *p, *pe, *data = buf + have;
int len, space = BUFSIZE - have;
/* fprintf( stderr, "space: %i\n", space ); */
if ( space == 0 ) {
fprintf(stderr, "buffer out of space\n");
exit(1);
}
len = fread( data, 1, space, stdin );
/* fprintf( stderr, "len: %i\n", len ); */
if ( len == 0 )
break;
/* Find the last newline by searching backwards. This is where
* we will stop processing on this iteration. */
p = buf;
pe = buf + have + len - 1;
while ( *pe != '\n' && pe >= buf )
pe--;
pe += 1;
/* fprintf( stderr, "running on: %i\n", pe - p ); */
%% write exec;
/* How much is still in the buffer. */
have = data + len - pe;
if ( have > 0 )
memmove( buf, pe, have );
/* fprintf(stderr, "have: %i\n", have ); */
if ( len < space )
break;
}
if ( have > 0 )
fprintf(stderr, "input not newline terminated\n");
return 0;
}
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