meillo@14: #
meillo@14: /* cut : cut and paste columns of a table (projection of a relation)  (GWRL) */
meillo@14: /* Release 1.5; handles single backspaces as produced by nroff    */
meillo@14: # include <stdio.h>	/* make: cc cut.c */
meillo@14: # define NFIELDS 512	/* max no of fields or resulting line length */
meillo@14: # define BACKSPACE 8
meillo@14: main(argc, argv)
meillo@14: int argc; char **argv;
meillo@14: {
meillo@14: 	int del = '\t';
meillo@14: 	int i, j, count, poscnt, r, s, t;
meillo@14: 	int endflag, supflag, cflag, fflag, backflag, filenr;
meillo@14: 	int sel[NFIELDS];
meillo@14: 	register int c;
meillo@14: 	register char *p1;
meillo@14: 	char *p2, outbuf[NFIELDS];
meillo@14: 	FILE *inptr;
meillo@14:  
meillo@14:  
meillo@14: while (argc > 1 && argv[1][0] == '-'){
meillo@14: 	for (i = 1; (c = argv[1][i]) != '\0'; i++) {
meillo@14: 		switch(c) {
meillo@14: 			case 'd' : del = argv[1][++i];
meillo@14: 				if (del == '\0') diag("no delimiter\n");
meillo@14: 				break;
meillo@14: 			case 's': supflag++ ;
meillo@14: 				break;
meillo@14: 			case 'c': cflag++ ;
meillo@14: 				break;
meillo@14: 			case 'f': fflag++ ;
meillo@14: 				break;
meillo@14: 			default : diag("Usage: cut [-s] [-d<char>] {-c<list> | -f<list>} file ...\n");
meillo@14: 				break;
meillo@14: 		}
meillo@14: 		if (!endflag && (cflag || fflag)) {
meillo@14: 			endflag = 1;
meillo@14: 			r = s = t = 0;
meillo@14: 			do {	c = argv[1][++i];
meillo@14: 				switch(c) {
meillo@14: 					case '-' : if (r) diagl();
meillo@14: 						r = 1;
meillo@14: 						if (t == 0)  s = 1;
meillo@14: 						else {s = t; t = 0;}
meillo@14: 						continue;
meillo@14: 					case '\0' :
meillo@14: 					case ','  : if (t >= NFIELDS) diagl();
meillo@14: 						if (r) { if (t == 0) t = NFIELDS - 1;
meillo@14: 							if (t<s) diagl();
meillo@14: 							for(j = s; j <= t; j++) sel[j] = 1;
meillo@14: 							}
meillo@14: 						else sel[t] = (t > 0 ? 1 : 0);
meillo@14: 						r = s = t = 0;
meillo@14: 						if (c == '\0') {i--; break;}
meillo@14: 						continue;
meillo@14: 					default :
meillo@14: 						if (c< '0' || c> '9') diagl();
meillo@14: 						t = 10*t + c - '0';
meillo@14: 						continue;
meillo@14: 				}
meillo@14: 				for (j = t = 0; j < NFIELDS; j++) t += sel[j];
meillo@14: 				if (t == 0) diag("no fields\n");
meillo@14: 			} while (c != '\0');
meillo@14: 		}
meillo@14: 	}
meillo@14: 	--argc;
meillo@14: 	++argv;
meillo@14: } /* end options */
meillo@14: if (!(cflag || fflag)) diagl();
meillo@14: 
meillo@14: --argc;
meillo@14: filenr = 1;
meillo@14: do {	/* for all input files */
meillo@14: 	if (argc > 0) inptr = fopen(argv[filenr], "r");
meillo@14: 	else inptr = stdin;
meillo@14:   
meillo@14: 	if (inptr == NULL) {
meillo@14: 		write(2,"Cannot open :",14);
meillo@14: 		diag(argv[filenr]);
meillo@14: 	}
meillo@14: 	endflag = 0;
meillo@14: 	do {	/* for all lines of a file */
meillo@14: 		count = poscnt = backflag = 0;
meillo@14: 		p1 = &outbuf[0] - 1 ;
meillo@14: 		p2 = p1;
meillo@14: 		do { 	/* for all char of the line */
meillo@14: 			c = fgetc(inptr);
meillo@14: 			if (c == EOF) {
meillo@14: 				endflag = 1;
meillo@14: 				break;
meillo@14: 				}
meillo@14: 			if (count == NFIELDS - 1) diag("line too long\n");
meillo@14: 			if (c != '\n') *++p1 = c;
meillo@14: 			if (cflag && (c == BACKSPACE)) backflag++ ; else 
meillo@14: 				{ if ( !backflag ) poscnt += 1 ; else backflag-- ;}
meillo@14: 			if ( backflag > 1 ) diag("cannot handle multiple adjacent backspaces\n");
meillo@14: 			if ( ((c == '\n') && count > 0)  || c == del || cflag) {
meillo@14: 				count += 1;
meillo@14: 				if (fflag) poscnt = count  ;
meillo@14: 				if (sel[poscnt]) p2 = p1; else p1 = p2;
meillo@14: 			}
meillo@14: 		}while (c != '\n');
meillo@14: 		if ( !endflag && (count > 0 || !supflag)) {
meillo@14: 			if (*p1 == del) *p1 = '\0';
meillo@14: 				else *++p1 = '\0'; /*suppress trailing delimiter*/
meillo@14: 			puts(outbuf);
meillo@14: 			}
meillo@14: 	} while (!endflag) ;
meillo@14: fclose(inptr);
meillo@14: } while(++filenr <= argc);
meillo@14: }
meillo@14: 
meillo@14: diag(s)
meillo@14: char *s;
meillo@14: {
meillo@14: 	write(2, "cut : ", 6);
meillo@14: 	while(*s)
meillo@14: 		write(2,s++,1);
meillo@14: 	exit(2);
meillo@14: }
meillo@14: diagl()
meillo@14: {
meillo@14: diag("bad list for c/f option\n");
meillo@14: }