Source Code 1992 March/Source_Code_CD-ROM_Walnut_Creek_March_1992.iso/usenet/compsrcs/unix/volume02/bm

Internet Message Format | 1988-09-11 | 24.4 KB

From: Peter Bain <decvax!watmath!wateng!pdbain>
Subject: bm version 1.1
Newsgroups: mod.sources
Approved: [e-mail]

Mod.sources:  Volume 2, Issue 14
Submitted by: Peter Bain <decvax!watmath!wateng!pdbain>


This is an fgrep-like Boyer-Moore program called "bm"
which is much faster than the bgrep program posted recently (see below).
I have found that for 99% of the cases bm is entirely sufficient.

        */bin/time bgrep Zurich /usr/dict/words
        Zurich
               38.7 real         7.3 user         1.1 sys
        */bin/time bm Zurich /usr/dict/words
        Zurich
                5.2 real         0.9 user         0.5 sys
        script done on Thu Jul  4 10:09:56 1985

1. Bug fixes from release 1.0:
    - incorrect operation of -x with -c, -s, -l. Fixed.
    - major bug, which was acute with piped input: lines containing
    matches were mangled or missed entirely. Fixed.
    - Some sites were having trouble with externs and #include files
    (the systems at Waterloo run 4.2, and we have not found this,
    but I have changed thing to make everyone happy.
    - Some compilers don't like line 36 of Search.c. I have
    added alternate code (line 39) against this possibility

    One site reported abnormally high system time. Installers may want to
    play around with MAXBUFF to optimize.

2. Added features:
    -e: take next argument as a pattern, even if it starts with a '-'
    -h: do not print file names.

3. Why bm is always case-sensitive.
    95% of the time I use a pattern matcher, I know the pattern exactly.
    If not, I use grep. I didn't consider the speed penalty worth it.

-------------- snip snip snip -----------------------------------------
: This is a shar archive.    Extract with sh, not csh.
: The rest of this file will extract:
: bm.h bm.c Execute.c Extern.h GetPatFile.c Global.c MakeDesc.c MakeSkip.c MatchFound.c MkDescVec.c MoveResidue.c PrintLine.c PutUsage.c Search.c Makefile README bm.p
echo Extracting bm.h
sed 's/^X//' > bm.h << 'e-o-f'
X#define FIRSTCHAR ' '
X#define MAXCHAR 0377
X#define MAXBUFF 8192
X#define MAXSIZE 100
X#define MAXPATS 100 /* max number of patterns */
X#define min(x,y) (x) < (y) ? (x) : (y)
X#define max(x,y) (x) > (y) ? (x) : (y)
Xstruct PattDesc {
X    int *Skip1, *Skip2; /* pointers to skip tables */
X    char *Pattern;
X    int PatLen; /* pattern length */
X    char *Start;
X    /* starting position of search (at beginning of pattern) */
X    int Success; /* true when pattern found */
X};
e-o-f
echo Extracting bm.c
sed 's/^X//' > bm.c << 'e-o-f'
X#include <stdio.h>
X#include <sys/file.h>
X#include <strings.h>
X#include "bm.h"
X#include "Extern.h"
Xmain(argc,argv)
Xint argc;
Xchar *argv[];
X{
X    /* test driver for grep based on Boyer-Moore algorithm */
X    char BigBuff[MAXBUFF + 2];
X    /*
X    * We leave one extra character at the beginning and end of the buffer,
X    * but don't tell Execute about it. This is so when someone is
X    * scanning the buffer and scans past the end (or beginning)
X    * we are still technically in the buffer (picky, but there ARE
X    * machines which would complain)
X    */
X    int ret = 1, /* return code from Execute */
X        NFiles,
X        NPats; /* number of patterns to search for */
X    char i,
X        *FlagPtr,
X        **OptPtr; /* used to scan command line */
X    int TextFile /* file to search */;
X    struct PattDesc *DescVec[MAXPATS];
X
X    --argc;
X    OptPtr = argv + 1;
X    while ( argc && **OptPtr == '-') {
X        FlagPtr = *OptPtr + 1;
X        while (*FlagPtr) {
X            switch (*FlagPtr) {
X                case 'c': cFlag = 1; break;
X                case 'e': eFlag = 1;
X                    /* get the patterns from next arg */
X                    NPats = MkDescVec(DescVec,*++OptPtr);
X                    --argc;
X                    break;
X                case 'f': fFlag = 1;
X                    /* read the patterns from a file */
X                    NPats = GetPatFile(*++OptPtr,DescVec);
X                    --argc;
X                    break;
X                case 'l': lFlag = 1; break;
X                case 'n': nFlag = 1; break;
X                case 's': sFlag = 1; break;
X                case 'x': xFlag = 1; break;
X                case 'h': hFlag = 1; break;
X                default:
X                    fprintf(stderr,
X                    "bm: invalid option: -%c \n",
X                    *FlagPtr);
X                    PutUsage();
X                    exit(2);
X            } /* switch */
X            ++FlagPtr;
X        } /* while */
X        ++OptPtr; --argc;
X    } /* while */
X    /* OptPtr now points to patterns */
X    if (!fFlag && !eFlag) {
X        if (!argc) {
X            fprintf(stderr,"bm: no pattern specified\n");
X            PutUsage();
X            exit(2);
X        } else
X            NPats = MkDescVec(DescVec,*OptPtr);
X        ++OptPtr; --argc;
X    }
X    /* OptPtr now points to first file */
X    NFiles = argc;
X    if (!NFiles)
X        ret &= Execute(DescVec,NPats,0,BigBuff+1);
X    else while (argc--) {
X        if ((NFiles > 1) || lFlag) FileName = *OptPtr;
X        if ((TextFile = open(*OptPtr,O_RDONLY,0)) < 0) {
X            fprintf(stderr,"bm: can't open %s\n",*OptPtr);
X            exit(2);
X        } /* if */
X        ret &= Execute(DescVec,NPats,TextFile,BigBuff+1);
X        if (sFlag && !ret)
X            exit(0);
X        ++OptPtr;
X        close(TextFile);
X    } /* while */
X    if (cFlag) printf("%d\n",MatchCount);
X    exit(ret);
X} /* main */
e-o-f
echo Extracting Execute.c
sed 's/^X//' > Execute.c << 'e-o-f'
X#include <stdio.h>
X#include "bm.h"
X#include "Extern.h"
XExecute(DescVec, NPats, TextFile, Buffer)
Xstruct PattDesc *DescVec[]; /* pointers to status vectors for the different
X    * patterns, including skip tables, position in buffer, etc. */
Xint NPats; /* number of patterns */
Xchar Buffer[]; /* holds text from file */
Xint TextFile; /* file to search */
X{
X    int NRead, /* number of chars read from file */
X        NWanted, /* number of chars wanted */
X        NAvail, /* number of chars actually read */
X        BuffSize, /* number of chars in buffer */
X        BuffPos, /* offset of first char in Buffer in TextFile */
X        BuffEx, /* flag to indicate that buffer has been searched */
X        ResSize,
X        /* number of characters in the last, incomplete line */
X        Found, /* flag indicates whether pattern found
X        * completely and all matches printed */
X        Valid; /* was the match "valid", i.e. if -x used,
X        * did the whole line match? */
X    char *BuffEnd; /* pointer to last char of last complete line */
X
X    /* misc working variables */
X    int i;
X
X    /* initialize */
X    ResSize = 0;
X    Found = 0;
X    BuffPos = 0;
X    for (i=0; i < NPats; i++) {
X        DescVec[i] -> Success = 0;
X        DescVec[i] -> Start = Buffer;
X    } /* for */
X    /* now do the searching */
X    do {
X        /* first, read a bufferfull and set up the variables */
X        NWanted = MAXBUFF - ResSize; NRead = 0;
X        do {
X            NAvail =
X               read(TextFile,Buffer + ResSize + NRead, NWanted);
X            if (NAvail == -1) {
X                fprintf(stderr,
X                  "bm: error reading from input file\n");
X                exit(2);
X            } /* if */
X            NRead += NAvail; NWanted -= NAvail;
X        } while (NAvail && NWanted);
X        BuffEx = 0;
X        BuffSize = ResSize + NRead;
X        BuffEnd = Buffer + BuffSize - 1;
X        /* locate the end of the last complete line */
X        while (*BuffEnd != '\n' && BuffEnd >= Buffer)
X            --BuffEnd;
X        if (BuffEnd < Buffer)
X            BuffEnd = Buffer + BuffSize - 1;
X        while (!BuffEx) { /* work through one buffer full */
X            BuffEx = 1; /* set it provisionally, then clear
X            * it if we find the buffer non-empty */
X            for (i=0; i< NPats; i++) {
X                if (!DescVec[i]->Success)
X                /* if the pattern  has not been found */
X                    DescVec[i]-> Success =
X                    Search(DescVec[i]->Pattern,
X                    DescVec[i]->PatLen, Buffer, BuffEnd,
X                    DescVec[i]->Skip1, DescVec[i]->Skip2,
X                    DescVec[i]);
X                if (DescVec[i]->Success){
X                /* if a match occurred */
X                    BuffEx = 0;
X                    Valid = MatchFound(DescVec[i],BuffPos,
X                    Buffer, BuffEnd);
X                    Found |= Valid;
X                    if ((sFlag || lFlag) && Found)
X                        return(0);
X                } /* if */
X            } /* for */
X        } /* while */
X        if(NRead) {
X            ResSize = MoveResidue(DescVec,NPats,Buffer,BuffEnd);
X            BuffPos += BuffSize - ResSize;
X        } /* if */
X    } while (NRead);
X    return(!Found);
X} /* Execute */
e-o-f
echo Extracting Extern.h
sed 's/^X//' > Extern.h << 'e-o-f'
X/* global flags for bm */
Xextern int    cFlag, /* true if we want only a count of matching lines */
X    eFlag, /* indicates that next argument is the pattern */
X    fFlag, /* true if the patterns arew to come from a file */
X    lFlag, /* true if we want a list of files containing the pattern */
X    nFlag, /* true if we want the character offset of the pattern */
X    sFlag, /* true if we want silent mode */
X    xFlag, /* true if we want only lines which match entirely */
X    hFlag, /* true if we want no filenames in output */
X
X    MatchCount; /* count of number of times a search string was found
X    * in the text */
Xextern char *FileName;
e-o-f
echo Extracting GetPatFile.c
sed 's/^X//' > GetPatFile.c << 'e-o-f'
X#include <stdio.h>
X#include <sys/types.h>
X#include <sys/stat.h>
X#include "bm.h"
Xint
XGetPatFile(PatFile, DescVec)
Xchar *PatFile;
Xstruct PattDesc *DescVec[];
X/* read patterns from a file and set up a pattern descriptor vector */
X{
X    extern char *malloc();
X    FILE *PFile;
X    struct stat StatBuff;
X    int PatSize; /* the number of chars in all the patterns */
X    char *PatBuff; /* hold the patterns */
X    if (!(PFile = fopen(PatFile,"r"))) {
X        fprintf(stderr,"bm: can't open pattern file %s\n",PatFile);
X        exit(2);
X    } /* if */
X    /* find out how big the patterns are */
X    if (fstat(fileno(PFile),&StatBuff) == -1) {
X        fprintf(stderr,"bm: can't fstat %s\n",PatFile);
X        exit(2);
X    } /* if */
X    PatSize = StatBuff.st_size;
X    if (!PatSize) {
X        fprintf(stderr,"bm: pattern file is empty\n");
X        exit(2);
X    } /* if */
X    if (!(PatBuff = malloc(PatSize))) {
X           fprintf(stderr,"bm: insufficient memory to store patterns\n");
X        exit(2);
X    } /* if */
X    fread(PatBuff,1,PatSize,PFile); /* get the patterns */
X    /* make sure the patterns are null-terminated. We can't have
X    * nulls in the patterns */
X    if (PatBuff[PatSize-1] == '\n')
X        PatBuff[PatSize-1] = '\0';
X    else
X        PatBuff[PatSize] = '\0';
X    return(MkDescVec(DescVec,PatBuff));
X} /* GetPatFile */
e-o-f
echo Extracting Global.c
sed 's/^X//' > Global.c << 'e-o-f'
X/* global flags for bm */
Xint    cFlag=0, /* true if we want only a count of matching lines */
X    eFlag=0, /* indicates that next argument is the pattern */
X    fFlag=0, /* true if the patterns are to come from a file */
X    lFlag=0, /* true if we want a list of files containing the pattern */
X    nFlag=0, /* true if we want the character offset of the pattern */
X    sFlag=0, /* true if we want silent mode */
X    xFlag=0, /* true if we want only lines which match entirely */
X    hFlag=0, /* true if we want no filenames in output */
X
X    MatchCount=0; /* count of number of times a search string was found
X    * in the text */
Xchar *FileName = 0;
e-o-f
echo Extracting MakeDesc.c
sed 's/^X//' > MakeDesc.c << 'e-o-f'
X#include <stdio.h>
X#include "bm.h"
X#include "Extern.h"
Xextern char * malloc();
X/* makes a pattern descriptor */
Xstruct PattDesc *MakeDesc(Pattern)
Xchar *Pattern;
X{
X    struct PattDesc *Desc;
X    Desc = (struct PattDesc *) malloc(sizeof(struct PattDesc));
X    if (!(Desc->Skip1 = (int *) malloc( sizeof(int) * (MAXCHAR + 1)))){
X        fprintf(stderr,"bm: can't allocate space\n");
X        exit(2);
X    } /* if */
X    if (!(Desc->Skip2 = (int *) malloc(sizeof(int) * strlen(Pattern)))){
X        fprintf(stderr,"bm: can't allocate space\n");
X        exit(2);
X    } /* if */
X    Desc->Pattern=Pattern;
X    Desc->PatLen = strlen(Desc->Pattern);
X    MakeSkip(Desc->Pattern,Desc->Skip1,
X    Desc->Skip2,Desc->PatLen);
X    return(Desc);
X} /* main */
e-o-f
echo Extracting MakeSkip.c
sed 's/^X//' > MakeSkip.c << 'e-o-f'
X#include "bm.h"
Xextern char *malloc();
X
XMakeSkip(Pattern,Skip1,Skip2,PatLen)
Xchar Pattern[];
Xint Skip1[], Skip2[];
Xint PatLen;
X/* generate the skip tables for Boyer-Moore string search algorithm.
X* Skip1 is the skip depending on the character which failed to match
X* the pattern, and Skip2 is the skip depending on how far we got into
X* the pattern. Pattern is the search pattern and PatLen is strlen(Pattern) */
X{
X    int *BackTrack; /* backtracking table for t when building skip2 */
X    int c; /* general purpose constant */
X    int j,k,t,tp; /* indices into Skip's and BackTrack */
X
X    if (!(BackTrack = (int *) malloc(PatLen * (sizeof (int))))){
X        fprintf("bm: can't allocate space\n");
X        exit(2);
X    } /* if */
X    for (c=0; c<=MAXCHAR; ++c)
X        Skip1[c] = PatLen;
X    for (k=0;k<PatLen;k++) {
X        Skip1[Pattern[k]] = PatLen - k - 1;
X        Skip2[k] = 2 * PatLen - k - 1;
X    } /* for */
X    for (j=PatLen - 1,t=PatLen;j >= 0; --j,--t) {
X        BackTrack[j] = t;
X        while (t<PatLen && Pattern[j] != Pattern[t]) {
X            Skip2[t] = min(Skip2[t], PatLen - j - 1);
X            t = BackTrack[t];
X        } /* while */
X    } /* for */
X    for (k=0;k<=t;++k)
X        Skip2[k] = min(Skip2[k],PatLen+t-k);
X    tp=BackTrack[t];
X    while(tp<PatLen) {
X        while(t<PatLen) {
X            Skip2[t] = min(Skip2[t],tp-t+PatLen);
X            ++t;
X        } /* while */
X        tp = BackTrack[tp];
X    } /* while */
X    cfree(BackTrack);
X} /* MakeSkip */
e-o-f
echo Extracting MatchFound.c
sed 's/^X//' > MatchFound.c << 'e-o-f'
X#include <stdio.h>
X#include "bm.h"
X#include "Extern.h"
XMatchFound(Desc, BuffPos, Buffer, BuffEnd)
Xstruct PattDesc *Desc; /* state info about search for one string */
Xint BuffPos; /* offset of first char of buffer into the file being searched */
Xchar *Buffer, /* pointer to the first character in the buffer */
X    *BuffEnd; /* pointer to the last character in the buffer */
X{
X    char *MLineBegin, *MLineEnd;
X    Desc->Success = 0;
X    /* Start points to first character after a successful match */
X    MLineBegin = MLineEnd = Desc->Start - 1;
X    while(MLineBegin >=Buffer && *MLineBegin != '\n') --MLineBegin;
X    ++MLineBegin;
X    while( MLineEnd <= BuffEnd && *MLineEnd != '\n') ++MLineEnd;
X    if (MLineEnd > BuffEnd) --MLineEnd;
X    /* fixed 25jun85 pdbain. suppress multiple matches of the same
X    * pattern on one line */
X    Desc->Start = MLineEnd + 1;
X    /* check if exact match */
X    if (xFlag && !( Desc->PatLen == (*MLineEnd != '\n' ? ((MLineEnd -
X    MLineBegin) + 1) : (MLineEnd - MLineBegin))))
X        return(0); /* failure */
X    if (sFlag) return(1);
X    if (cFlag) {
X        ++MatchCount;
X        return(1);
X    } /* if */
X    PrintLine(BuffPos+(Desc->Start-Buffer),MLineBegin,MLineEnd);
X    return(1);
X} /* MatchFound */
e-o-f
echo Extracting MkDescVec.c
sed 's/^X//' > MkDescVec.c << 'e-o-f'
X#include "bm.h"
X#include <strings.h>
X/* scan a newline-separated string of patterns and set up the
X* vector of descriptors, one pattern descriptor per pattern.
X* Return the number of patterns */
Xint
XMkDescVec(DescVec, Pats)
Xstruct PattDesc *DescVec[];
Xchar *Pats;
X{
X    int NPats = 0;
X    char *EndPat;
X    extern struct PattDesc *MakeDesc();
X    while (*Pats && (EndPat = index(Pats,'\n')) && NPats < MAXPATS) {
X        *EndPat = '\0';
X        DescVec[NPats] = MakeDesc(Pats);
X        Pats = EndPat + 1;
X        ++NPats;
X    } /* while */
X    if (*Pats && NPats < MAXPATS) {
X        DescVec[NPats] = MakeDesc(Pats);
X        ++NPats;
X    } /* if */
X    return(NPats);
X} /* MkDescVec */
e-o-f
echo Extracting MoveResidue.c
sed 's/^X//' > MoveResidue.c << 'e-o-f'
X#include "bm.h"
X/* Moves the text which has not been completely searched at the end of
X* the buffer to the beginning of the buffer
X* and returns number of bytes moved */
Xint MoveResidue(DescVec, NPats,Buffer, BuffEnd)
Xstruct PattDesc *DescVec[];
Xint NPats;
Xchar *Buffer, *BuffEnd;
X{
X    char *FirstStart, *f, *t, *Residue;
X    int ResSize, i;
X    FirstStart = BuffEnd;
X    /* find the earliest point which has not been
X    * completely searched */
X    for (i=0; i < NPats; i++) {
X        FirstStart =
X            min(FirstStart, DescVec[i]-> Start );
X    } /* for */
X    /* now scan to the beginning of the line containing the
X    * unsearched text */
X    for (Residue = FirstStart; *Residue != '\n' &&
X    Residue >= Buffer; Residue--);
X    if (Residue < Buffer)
X        Residue = FirstStart;
X    else ++Residue;
X    ResSize = (BuffEnd - Residue + 1);
X    /* now move the residue to the beginning of
X    * the file */
X    t = Buffer; f = Residue;
X    for(i=ResSize;i;--i)
X        *t++ = *f++;
X    /* now fix the status vectors */
X    for (i=0; i < NPats; i++) {
X        DescVec[i]->Start -= (Residue - Buffer);
X    } /* for */
X    return(ResSize);
X} /* MoveResidue */
e-o-f
echo Extracting PrintLine.c
sed 's/^X//' > PrintLine.c << 'e-o-f'
X#include <stdio.h>
X#include <strings.h>
X#include "Extern.h"
XPrintLine(OffSet,LineStart,LineEnd)
Xint OffSet; /* offset of LineStart from beginning of file */
Xchar *LineStart,
X    *LineEnd;
X{
X    char OffStr[80];
X    if (lFlag) {
X        if (strlen(FileName) > 76) {
X            fprintf(stderr,"bm: filename too long\n");
X            exit(2);
X        } /* if */
X        sprintf(OffStr,"%s\n",FileName);
X        write(1,OffStr,strlen(OffStr));
X        return;
X    } /* if */
X    if (FileName && !hFlag) {
X        if (strlen(FileName) > 76) {
X            fprintf(stderr,"bm: filename too long\n");
X            exit(2);
X        } /* if */
X        sprintf(OffStr,"%s:",FileName);
X        write(1,OffStr,strlen(OffStr));
X    } /* if */
X    if (nFlag) {
X        sprintf(OffStr,"%d: ",OffSet);
X        write(1,OffStr,strlen(OffStr));
X    } /* if */
X    write(1,LineStart,LineEnd-LineStart+1);
X    if (*LineEnd != '\n') write (1,"\n",1);
X} /* PrintLine */
e-o-f
echo Extracting PutUsage.c
sed 's/^X//' > PutUsage.c << 'e-o-f'
X#include <stdio.h>
XPutUsage()
X{
X    fprintf(stderr,
X    "bm: search for a given string or strings in a file or files\n");
X    fprintf(stderr,
X    "synopsis: bm [option]* [string(s)] [file]*\n");
X    fprintf(stderr,
X    "options:\n");
X    fprintf(stderr,
X    "-c print only a count of matching lines \n");
X    fprintf(stderr,
X    "-e Take next argument as the pattern\n");
X    fprintf(stderr,
X    "-f PFile read patterns from a file PFile\n");
X    fprintf(stderr,
X    "-h Do not print file names\n");
X    fprintf(stderr,
X    "-l print a list of files containing the pattern(s) \n");
X    fprintf(stderr,
X    "-n print the character offset of the pattern(s) \n");
X    fprintf(stderr,
X    "-s silent mode. Return only success (0) or failure (1)\n");
X    fprintf(stderr,
X    "-x print only lines which match entirely \n");
X} /*PutUsage */
e-o-f
echo Extracting Search.c
sed 's/^X//' > Search.c << 'e-o-f'
X#include "bm.h"
X#include "Extern.h"
Xint Search(Pattern,PatLen,Buffer, EndBuff, Skip1, Skip2, Desc)
Xchar Pattern[];
Xint PatLen;
Xchar Buffer[];
Xchar *EndBuff;
Xint Skip1[], Skip2[];
Xstruct PattDesc *Desc;
X{
X    register char *k, /* indexes text */
X        *j, /* indexes Pattern */
X        *PatBegin; /* register pointing to char
X        * before beginning of Pattern */
X    register int Skip; /* skip distance */
X    char *PatEnd,
X    *BuffEnd; /* pointers to last char in Pattern and Buffer */
X    BuffEnd = EndBuff;
X    PatBegin = Pattern - 1;
X    PatEnd = Pattern + PatLen - 1;
X
X    k = Desc->Start;
X    Skip = PatLen-1;
X    while ( Skip <= (BuffEnd - k) ) {
X        j = PatEnd;
X        k = k + Skip;
X        while (j > PatBegin && *j == *k) {
X            --j; --k;
X        } /* while */
X        if (j< Pattern) {
X            /* found it. Start next search
X            * just after the pattern */
X            Desc -> Start = k + 1 + Desc->PatLen;
X            return(1);
X        } /* if */
X        Skip = max(Skip1[*(unsigned char *)k],Skip2[j-Pattern]);
X    } /* while */
X    Desc->Start = k;
X    return(0);
X} /* Search */
e-o-f
echo Extracting Makefile
sed 's/^X//' > Makefile << 'e-o-f'
XCCFLAGS =  -O
XSOURCES =  bm.h bm.c Execute.c Extern.h\
X    GetPatFile.c Global.c MakeDesc.c MakeSkip.c \
X    MatchFound.c \
X    MkDescVec.c MoveResidue.c PrintLine.c PutUsage.c Search.c
XOBJECTS = bm.o Execute.o \
X    GetPatFile.o Global.o MakeDesc.o MakeSkip.o \
X    MatchFound.o \
X    MkDescVec.o MoveResidue.o Search.o PrintLine.o PutUsage.o
XBASEFILES = $(SOURCES) Makefile README bm.p
Xbm: $(OBJECTS)
X    cc -o bm $(CCFLAGS) $(OBJECTS)
Xinstall: bm
X    rm /usr/public/bm
X    cp bm /usr/public/bm
X    rm /usr/src/public/bm/*
X    cp $(BASEFILES) /usr/src/public/bm
Xshar:
X    /usr/public/shar $(BASEFILES) >bm.shar
Xman: /usr/man/manp/bm.p
X/usr/man/manp/bm.p: bm.p
X    rm -f /usr/man/manp/bm.p
X    cp bm.p /usr/man/manp/bm.p
X    man bm > /dev/null
Xbm.o: bm.c bm.h Extern.h
X    cc -c $(CCFLAGS) bm.c
XPutUsage.o: PutUsage.c bm.h
X    cc -c $(CCFLAGS) PutUsage.c
XMakeSkip.o: MakeSkip.c bm.h
X    cc -c $(CCFLAGS) MakeSkip.c
XSearch.o: Search.c bm.h Extern.h
X    cc -c $(CCFLAGS) Search.c
XExecute.o: Execute.c bm.h
X    cc -c $(CCFLAGS) Execute.c
XMoveResidue.o: MoveResidue.c bm.h Extern.h
X    cc -c $(CCFLAGS) MoveResidue.c
XMatchFound.o: MatchFound.c bm.h Extern.h
X    cc -c $(CCFLAGS) MatchFound.c
XPrintLine.o: PrintLine.c Extern.h
X    cc -c $(CCFLAGS) PrintLine.c
XMkDescVec.o: MkDescVec.c bm.h
X    cc -c $(CCFLAGS) MkDescVec.c
XGetPatFile.o: GetPatFile.c bm.h
X    cc -c $(CCFLAGS) GetPatFile.c
XMakeDesc.o: MakeDesc.c bm.h
X    cc -c $(CCFLAGS) MakeDesc.c
XGlobal.o: Global.c
X    cc -c $(CCFLAGS) Global.c
Xlisting:
X    print -i3 $(BASEFILES)
e-o-f
echo Extracting README
sed 's/^X//' > README << 'e-o-f'
XBm is a fast pattern matching utility, intended to be almost
Xidentical in functionality to fgrep (ugh!) but much faster. It uses
Xthe Boyer-Moore algorithm, as described in the papers listed below:
X
XD.E. Knuth, J.H. Morris, V.R. Pratt,"Fast Pattern Matching in Strings",
XSIAM J. Comput., 6(2), June  1977, 323-350,
X
XZ. Galil,
X"On Improving the Worst Case Running Time of the Boyer-Moore String
XMatching Algorithm",
XCACM, 22(9), Sept. 1979, ACM,
X
XR.S. Boyer, J.S. Moore,"A Fast String Searching Algorithm", CACM, 20(10),
XOct. 1977, 762-772,
X
XG. de V. Smit,"A Comparison of Three String Matching Algorithms",
XSoftware - Practice and Experience, vol. 12,  1982, 57-66,
X
XThe files are:
XExecute.c: search a file for the patterns
XExtern.h: declarations of externs
XGetPatFile.c: read in patterns from a file and set up a vector of
X    pattern descriptors
XGlobal.c: global variables (complement to Extern.h)
XMakeDesc.c: create a pattern descriptor for one pattern, including
X    skip tables, etc.
XMakeSkip.c: make the skip tables for one pattern
XMakefile: you can figure this one out for yourself
XMatchFound.c: what to do when you actually FIND a pattern - print it,
X    update flags, etc.
XMkDescVec.c: make a vector of pattern descriptors, given a string
X    of newline-separated patterns
XMoveResidue.c: when you come to the end of the buffer, move the
X    unsearched "residue" to the beginning and start again
XPrintLine.c: print the appropriate stuff after finding a match
XPutUsage.c: mini-man page.
XREADME: this file
XSearch.c: the guts. Implements B-M algorithm given a pattern, skip
X    tables for the pattern, and a buffer to search
Xbm.c: mainline. mostly interpreting the command line and tidying
X    up at the end. Calls Execute for each file.
Xbm.h: constants
Xbm.p: man page
e-o-f
echo Extracting bm.p
sed 's/^X//' > bm.p << 'e-o-f'
X.TH BM PUBLIC "8 July 1985"
X.UC 4
X.SH NAME
Xbm \- search a file for a string
X.SH SYNOPSIS
X.B /usr/public/bm
X[ option ] ...
X[ strings ]
X[ file ]
X.SH DESCRIPTION
X.I Bm
Xsearches the input
X.I files
X(standard input default) for lines matching a string.
XNormally, each line found is copied to the standard output.
XIt is blindingly fast.
X.I Bm
Xstrings are fixed sequences of characters:
Xthere are no wildcards, repetitions, or other features
Xof regular expressions.
XBm is also case sensitive.
XThe following options are recognized.
X.TP
X.B \-x
X(Exact) only lines matched in their entirety are printed
X.TP
X.B \-l
XThe names of files with matching lines are listed (once) separated by newlines.
X.TP
X.B \-c
XOnly a count of the number of matches
Xis printed
X.TP
X.B \-e "string"
XThe string is the next argument after the
X.B \-e
Xflag. This allows strings beginning with '-'.
X.TP
X.B \-h
XNo filenames are printed, even if multiple files are searched.
X.TP
X.B \-n
XEach line is preceded by the number
Xof characters from the beginning of the file
Xto the match.
X.TP
X.B \-s
XSilent mode.  Nothing is printed (except error messages).
XThis is useful for checking the error status.
X.TP
X.BI \-f " file"
XThe string list
Xis taken from the
X.I file.
X.LP
XUnless the
X.B \-h
Xoption is specified
Xthe file name is shown if there is more than one input file.
XCare should be taken when using the characters $ * [ ^ | ( ) and \\ in the
X.I strings
X(listed on the command line)
Xas they are also meaningful to the Shell.  It is safest to enclose the entire
X.I expression
Xargument in single quotes \' \'.
X.LP
X.I Bm
Xsearches for lines that contain one of the (newline-separated)
X.I strings,
Xusing
Xthe Boyer-Moore algorithm.
XIt is far superior in terms of speed to the grep (egrep, fgrep)
Xfamily of pattern matchers for fixed-pattern searching,
Xand its speed increases with pattern length.
X.SH "SEE ALSO"
Xgrep(1)
X.SH DIAGNOSTICS
XExit status is 0 if any matches are found,
X1 if none, 2 for syntax errors or inaccessible files.
X.SH AUTHOR
XPeter Bain (pdbain@wateng), with modifications suggested by John Gilmore
X.SH BUGS
XOnly 100 patterns are allowed.
X.LP
XPatterns may not contain newlines.
X.LP
XIf a line (delimited by newlines, and the beginning and end of the file)
Xis longer than 8000 charcters (e.g. in a core dump),
Xit will not be completely printed.
X.LP
XIf multiple patterns are specified, the order of the ouput lines is not
Xnecessarily the same as the order of the input lines.
X.LP
XA line will be printed once for each different string on that line.
X.LP
XThe algorithm cannot count lines.
X.LP
XThe
X.B -n
Xand
X.B -c
Xwork differently from fgrep.
X.LP
XThe
X.B -v,
X.B -i,
Xand
X.B -b
Xare not available.
e-o-f
exit 0