/*
Program: SEARCH
Author : Kim Moser
Date   : 4/12/89
System : IBM PC / Borland Turbo-C 2.0
Descrip: Searches files whose names are specified at stdin for any
	 occurence of bytes in file named argv[1].
	 Prints names of matching files to stdout, and offset where
	 text was found to stderr.

Usage  : SEARCH @<file> | <text>   [-<switches>] [[-]<offset> [<length>]]
	 Where <file> is file containing bytes to be searched for,
	 or <text> indicates literal text to be searched for.
	 Note: If first character of text is '@', pass text as "@text",

	 SWITCH MEANING
	      c case-insensitive search
	      O suppress displaying of offsets
	      M suppress displaying of messages
	      W suppress displaying of warnings
*/

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <io.h>
#include <fcntl.h>
#include <string.h>

int MSG=1, WARN=1, OFFSET=1;

long int LEN;  /* Length of text to be searched for */
char *TEXT=NULL;  /* Text to search for (will be allocated later) */
char *FBUF=NULL;  /* Buffer for files to be searched (will be allocated later) */
int ignorecase=0;
long int OFS=0, LENGTH=-1;  /* Offset and # bytes (from offset) to search for TEXT */
/* (-1 indicates not specified, so default to EOF */
char FROMEND=0;  /* Whether OFS is from EOF (0=BOF, 1=EOF) */

void credits(void)
{
	static int yet=0;

	if (!yet++ && MSG)
		fprintf( stderr, "SEARCH v1.0 (4/12/89)  Copyright (c) 1989 Kim Moser  All Rights Reserved\n" );
}

void usage(void)
{
	credits();
	if (!MSG) return;
	fprintf( stderr, "  Searches files whose names are specified at stdin for any occurence\n" );
	fprintf( stderr, "  occurence of bytes in file named argv[1].  Prints names of matching files\n" );
	fprintf( stderr, "  to stdout, and offset where text was found to stderr.\n\n" );
	fprintf( stderr, "  Usage: SEARCH @<file> | <text>   [[-]<switches>] [<offset>[-] [<length>]]\n" );
	fprintf( stderr, "    where <file> is file containing bytes for which to search, or\n" );
	fprintf( stderr, "    <text> indicates literal text for which to be searched.\n\n" );
	fprintf( stderr, "    SWITCH  MEANING\n" );
	fprintf( stderr, "         c  case-insensitive search\n" );
	fprintf( stderr, "         O  suppress offsets\n" );
	fprintf( stderr, "         M  suppress messages\n" );
	fprintf( stderr, "         W  suppress warnings\n" );
	exit(1);
}

void dofile(f)
char *f;
/* Searches file 'f' for TEXT of length LEN */
{
	FILE *fp;
	long int flen;
	long int sofar=0;
	int result;
	int nameyet=0;  /* Whether filename was printed yet */
	long int i;
	char *spot;
	unsigned long int shift;  /* # bytes to shift (0=none) */
	long int adj;  /* Adjusted (from BOF) OFS (note: will be == OFS if !FROMEND */
	long int run;  /* Run length adjusted for OFS, FROMEND, and flen */

/*
	fprintf( stderr, "Searching for: '" );
	for (i=0; i<LEN; i++) fprintf( stderr, "%c", TEXT[i]);
	fprintf( stderr, "'\n");
*/

	if ( (fp=fopen(f,"r")) == NULL ) {
		if (WARN)
			fprintf( stderr, "Unable to open file '%s' for reading.\n", f );
		return;  /* There might be more files to process */
	}

	if ( setmode(fileno(fp),O_BINARY) == -1 ) {
		if (WARN)
			fprintf( stderr, "Unable to set mode of '%s' to O_BINARY.\n", f );
		fclose(fp);
		return;  /* There might be more files to process */
	}

	if ((flen=filelength(fileno(fp))) == -1 ) {
		if (WARN)
			fprintf( stderr, "Unable to get length of file '%s'.\n", f );
		fclose(fp);
		return;  /* There might be more files to process */
	}
	adj = FROMEND ? flen-OFS-1 : OFS;
	run = LENGTH==-1?(FROMEND?flen-adj:flen-OFS):LENGTH;

	if (MSG)
		fprintf( stderr, "File '%s': %ld bytes", f, flen );

	/* If (offset brings us past BOF or EOF) or (run will be < text len)
	      or (run will go past EOF): */
	if ( (!FROMEND)&&( /*(OFS>=flen)||*/ (run<LEN)||(run+OFS>flen))||
		FROMEND&&( (OFS>=flen)||(run<LEN)||(run+adj>flen)) ) {
		if (MSG)
			fprintf( stderr, " (too short to search)\n" );
		fclose(fp);
		return;  /* There might be more files to process */
	}

	if (MSG) {
		fprintf( stderr, " (ofs=%s%ld", (FROMEND?"-":""), OFS );
		if (FROMEND)
			fprintf( stderr, " (%ld from beginning)", adj );
		fprintf( stderr, ", run=%ld)\n", run );
	}

	if ( fseek(fp,adj,SEEK_SET) ) {
		if (WARN)
			fprintf( stderr, "Unable to set file pointer for file '%s' to %ld.\n", f, adj );
		fclose(fp);
		return;  /* There might be more files to process */
	}

	/* Fill 'FBUF' with first 'LEN' bytes from 'fp': */
	for (i=0; i<LEN; i++) {
		if ((result=getc(fp))==EOF) {
			if (WARN)
				fprintf( stderr, "Able to read only the first %ld bytes from '%s'.\n", i+1, f );
			fclose(fp);
			return;  /* There might be more files to process */
		}
		FBUF[i]=result;
	}
	sofar = i;
	if (ignorecase)
		for (i=0; i<LEN; i++)
			FBUF[i]=toupper(FBUF[i]);

	while(1) {
/*
		fprintf( stderr, "Contents of buffer: '" );
		for (i=0; i<LEN; i++) fprintf( stderr, "%c", FBUF[i]);
		fprintf(stderr, "'\n" );
*/

		/* Search for text: */
		if (!memcmp(FBUF,TEXT,(size_t)LEN)) {  /* Found match! */
			if (!nameyet++)
				printf("%s\n", f);  /* Always printed */
			if (OFFSET)  /* Print the offset where text was found */
				fprintf(stderr," %ld", (long int) sofar-LEN);
		}

		/* Find spot in FBUF (not counting FBUF[0]) where first
		   occurrence of TEXT[0] exists: */
		if ( (spot=memchr(FBUF+1,TEXT[0],(size_t)LEN-1)) == NULL ) {
			shift=0;
		} else {
			shift=spot-FBUF;
		}

		if (shift)
			memmove(FBUF,FBUF+shift,(size_t)(LEN-shift));
		else
			shift=LEN;  /* So that next line fills entire buffer */

/*
		if (sofar>=run) {  /* We're done before we have to read any more bytes */
			break;
		}
*/
		for (i=LEN-shift; i<LEN; i++) {
			if ( (((result=getc(fp))==EOF) || (sofar==run)) ) {
				i=0;  /* So that we'll get out of entire loop */
				break;
			}
			sofar++;
			FBUF[i]=result;
			if (ignorecase)
				FBUF[i]=toupper(FBUF[i]);
		}
		if (i==0) break;
	}

	/* This should never happen: */
	if (sofar != run) {
		if (WARN)
			fprintf( stderr, "Read only %ld of %ld bytes.\n", sofar, run );
	}

/*
	if ((result=ftell(fp))==-1) {
		if (WARN)
			fprintf( stderr, "Unable to read file pointer for file '%s'.\n", f );
		fclose(fp);
		return;  /* There might be more files to process */
	}

	if (result-adj-1!=run) {
		fprintf( stderr, "Read only %ld of %ld bytes.\n", result-adj-1, run );
	}
*/

	if (fclose(fp)) {
		if (WARN)
			fprintf( stderr, "Unable to close file '%s'.\n", f );
		return;  /* There might be more files to process */
	}

	if (nameyet && OFFSET)
		fprintf( stderr, "\n" );
}

void parseswitches(s)
/* Parses switches from string 's' */
char *s;
{
	int i;

	for (i=0; s[i]; i++)
		switch(s[i]) {
			case 'c':
				ignorecase=1;
				break;
			case 'O':  /* Suppress offsets */
				OFFSET=0;
				break;
			case 'M':  /* Suppress msgs */
				MSG=0;
				break;
			case 'W':  /* Suppress warnings */
				WARN=0;
				break;
			default:
				usage();
				break;
		}
}

void parseoffset(s)
char *s;
{
	FROMEND=(s[strlen(s)-1]=='-');  /* Trailing '-' indicates from EOF */
	if ( sscanf(s,"%ld",&OFS)!=1 ) usage();
}

void parselength(s)
char *s;
{
	if ( sscanf(s,"%ld",&LENGTH)!=1 ) usage();
}

void main(argc, argv)
int argc;
char **argv;
{
	int i;
	FILE *fp;  /* File containing bytes to be searched for */
	char *fname=NULL;  /* Name of file containing bytes to be searched for */
	char filename[255];  /* Gets filled with name of file to search */
	char switchyet=0, offsetyet=0, lengthyet=0;

/*
	Usage  : SEARCH @<file> | <text>   [-<switches>] [<offset>[-] [<length>]]
		 0      1                  2             2/3          3/4
*/

	if (argc<2) usage();

	for (i=2; i<argc; i++)
		if (argv[i][0]=='-') {
			if (!switchyet++)
				parseswitches(argv[i]+1);
			else
				usage();
		} else {
			if (isdigit(argv[i][0])) {
				if (!offsetyet++) {
					parseoffset(argv[i]);
				} else {
					if (!lengthyet++)
						parselength(argv[i]);
					else
						usage();  /* Extra params */
				}
			} else
				usage();  /* Unknown param */
		}

	fname=argv[1];
	if (fname[0]!='@') {
		TEXT=strdup(fname);
		  /* Make a copy since we'll want to free it later */
		LEN=(long int) strlen(TEXT);
		if (MSG)
			fprintf( stderr, "Search for literal text: '%s'.\n", TEXT );
	} else {
		fname++;  /* Point past leading '@' */
		/* Get text to be searched for: */
		if ((fp=fopen(fname,"r")) == NULL) {
			if (WARN)
				fprintf( stderr, "Unable to open file containing bytes to be searched for: '%s'.\n", fname );
			exit(1);
		}
		if (setmode(fileno(fp), O_BINARY) == -1) {
			if (WARN)
				fprintf( stderr, "Unable to set mode of file '%s' to O_BINARY.\n", fname );
			exit(1);
		}

		/* Get file length */
		if ( (LEN=filelength(fileno(fp)))==-1 ) {
			if (WARN)
				fprintf( stderr, "Unable to get file length of file '%s'.\n", fname );
			exit(1);
		}

		/* Allocate space for text to be searched for: */
		if ((TEXT=(char*)malloc((size_t)LEN))==NULL) {
			if (WARN)
				fprintf( stderr, "Unable to allocate enough room for buffer for file '%s'.\n", fname );
			exit(1);
		}

		/* Read all LEN bytes of 'fp' into TEXT: */
/*
		for (i=0; i<LEN; i++) {
			if ((result=getc(fp))==EOF) {
				if (WARN)
					fprintf( stderr, "Able to read only the first %ld bytes from '%s'.\n", i+1, fname );
				free(TEXT);
				fclose(fp);
				exit(1);
			}
			TEXT[i]=result;
		}
*/

		if ( read(fileno(fp),TEXT,LEN) != LEN ) {
			if (WARN)
				fprintf( stderr, "Unable to read %ld bytes from file '%s'.\n", LEN, fname );
			free(TEXT);
			exit(1);
		}

		if (fclose(fp))
			if (WARN)
				fprintf( stderr, "Unable to close data file '%s'.\n", fname );
	}

	/* Allocate space for input file: */
	if ((FBUF=(char*)malloc((size_t)LEN)) == NULL) {
		if (WARN)
			fprintf( stderr, "Unable to allocate room for file buffer.\n" );
		exit(1);  /* This is a serious error */
	}

	if (ignorecase)
		for (i=0; i<LEN; i++)
			TEXT[i]=toupper(TEXT[i]);

	if (MSG) {
		fprintf( stderr, "Case %ssensitive\n", ignorecase?"in":"" );
		if (offsetyet) {
			fprintf( stderr, "Offset=%ld, Length=", OFS );
			if (lengthyet)
				fprintf( stderr, "%ld\n", LENGTH );
			else
				fprintf( stderr, "(Entire file)\n" );
		} else
			fprintf( stderr, "Search entire file\n" );
	}

	while (scanf("%s\n", filename)==1) {
		dofile(filename);
	}

	free(TEXT);
	free(FBUF);
}