/* fb.c File Browser
    Author: John Howard Swaby
   Version: 1.5
      Date: 2 May 1999

Copyright (C) 1998, 1999 John Howard Swaby

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

John Howard Swaby
polymath@uwyo.edu */

/* For MS-DOS */
/* #define MSDOS */

/* For Linux running on a PC:  Used below
   to exclude non-printable characters */
/* #define LINUX_PC */

/* For the Borland compiler:  Used below because Borland
   uses chsize whereas everyone else uses ftruncate */
/* #define BORLAND */

/* For compilers without data type long long */
/* #define LONG_ONLY */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>

#ifdef MSDOS
#include <io.h>
/* DOS_BINARY should be defined as the flag used in open(...) to
   read files as binary -- this might be found in fcntl.h */
#define DOS_BINARY O_BINARY
#else
#define DOS_BINARY 0
#endif

#define STDIN 0

short command(int);
void  setHeader(char*,char*,short);
short finishLine(char*,char*,short);
void  setWidth(char*);
void  setFormat(char*);
char* isNum(char*,short);
short clrInput(char*,short);
void  contin(char*);
void  diff(char**,char*);
void  chng(char**,char*);
void  move(int,char**,char*);
void  tran(int,char**,char*,char,unsigned short);
void  listCmds1(short);
void  listCmds2(void);
void  usage(char*,short);
void  info(char**,char*);
void  help(char*);

unsigned short bk, noStop = 1, edit = 0, compress = 0;
unsigned short ln = 0, rw = 16, rl, len, charOnly, showChar = 1,
 interact = 1, head = 1, err, cnt = 1, inc = 0, base, usrWidth = 0;
#ifdef LONG_ONLY
unsigned long fpos, stop, start = 0, mfpos = 0, ofpos = 0;
#else
unsigned long long fpos, stop, start = 0, mfpos = 0, ofpos = 0; 
#endif
long efpos, delta;
unsigned char c;
char fill[10], fs[6], hs[6], oh[2048], h[2048];
char *sp, numerals[23];
int fd = STDIN;

int main(int argc,char** argv)
{
   unsigned short ok = 1, argLast, lastArg, showAddr = 1;
   unsigned short j, i = 0, cont, argIdx, sl, cmd;
   char *p, *t, s[2048], line[2048], buffer[129], sc[2];

   t = p = *argv;
   while( *p ) {
      #ifdef MSDOS
      if( *p=='\\' )
      #else
      if( *p=='/' )
      #endif
         t = p;
      ++p;
   }
   p = *(t+1)&&t!=*argv?t+1:t;
   #ifdef MSDOS
   t = p;
   while( *t )
      if( *t=='.' )
         *t = '\0';
      else
         ++t;
   #endif
   if( argc==1 )
      usage(p,0);
   strcpy(numerals,"fedcbaFEDCBA9876543210");
   if( argc==3&&argv[1][0]=='-'&&!argv[1][1]&&!argv[2][1] )
      info(argv,p);
   else if( argc==4&&(argv[1][0]=='b'||argv[1][0]=='d'||argv[1][0]=='h'||
    argv[1][0]=='o'||argv[1][0]=='-'||argv[1][0]=='.')&&!argv[1][1] )
      diff(argv,p);
   else if( argc==5&&argv[1][0]=='r'&&!argv[1][1] )
      chng(argv,p);
   else if( 3<argc&&argc<6&&(argv[1][0]=='a'||argv[1][0]=='c')&&!argv[1][1] )
      move(argc,argv,p);
   else if( 2<argc&&argc<6&&argv[1][0]=='t'&&((j=(argc==3))||!argv[1][1])&&
    (argv[2-j][0+j]=='b'||argv[2-j][0+j]=='d'||argv[2-j][0+j]=='h'||
    argv[2-j][0+j]=='o')&&!argv[2-j][1+j] )
      tran(argc,argv,p,argv[2-j][0+j],j);
   argIdx = 1;
   s[0] = 'h'; s[1] = '\0'; sc[1] = '\0';
   argLast = lastArg = argc - 1;
   if( argc>2 ) {
      while( argIdx<argLast ) {
         if( argLast==argc&&argIdx==argLast-1 ) {
            if( strcmp(argv[argIdx],"-") )
               usage(p,1); }
         else if( argv[argIdx][0]=='-'&&(sc[0]=argv[argIdx][1]) ) {
            if( strstr("ipr",sc)&&!argv[argIdx][2] ) {
               switch( argv[argIdx][1] ) {
               case 'r':
                  if( ++argIdx<lastArg&&isNum(argv[argIdx],2) ) {
                     start=strtol(argv[argIdx],(char**)NULL,10);
                     noStop = 1;
                     if( (sp=strstr(argv[argIdx],"."))&&sp[1] ) {
                        #ifdef LONG_ONLY
                        stop = strtoul(sp+1,(char**)NULL,10);
                        #else
                        stop = strtoull(sp+1,(char**)NULL,10);
                        #endif
                        noStop = 0;
                     } }
                  else
                     usage(p,1);
                  break;
               case 'p':
                  if( ++argIdx<lastArg&&isNum(argv[argIdx],2) ) {
                     rl=atoi(argv[argIdx]);
                     rw = rl>64?64:rl?rl:16;
                     usrWidth = 0; ln = 0;
                     if( (sp=strstr(argv[argIdx],"."))&&sp[1] ) {
                        ln = atoi(sp+1);
                        ln = ln>128?128:ln;
                        usrWidth = (ln!=0);
                     } }
                  else
                     usage(p,1);
                  break;
               case 'i':
                  if( ++argIdx<lastArg&&isNum(argv[argIdx],0) ) {
                     delta = strtol(argv[argIdx],(char**)NULL,10);
                     inc = (delta!=0); }
                  else
                     usage(p,1);
               } }
            else {
               sp = argv[argIdx]+1;
               while( *sp&&ok ) {
                  sc[0] = *sp;
                  if( ok=(strstr("AaBbCcDdEeHhKkLlNnOoSsTt",sc)!=NULL) ) {
                     if( strstr("BbCcDdHhOo",sc) )
                        s[0] = *sp;
                     else if( *sp=='A'||*sp=='a' )
                        showAddr = (*sp=='A');
                     else if( *sp=='K'||*sp=='k' )
                        compress = (*sp=='k');
                     else if( *sp=='E'||*sp=='e' )
                        edit = (*sp=='e');
                     else if( *sp=='L'||*sp=='l' )
                        head = (*sp=='L');
                     else if( *sp=='N'||*sp=='n' )
                        showChar = (*sp=='N');
                     else if( strstr("SsTt",sc) ) {
                        interact = *sp=='S'?1:strstr("st",sc)?0:interact;
                        argLast = *sp=='t'?argc:argLast;
                        argLast = *sp=='T'||*sp=='S'?argc-1:argLast;
                     } }
                  else
                     usage(p,1);
                  ++sp;
               }
            } }
         else
            usage(p,1);
         ++argIdx;
      }
      showAddr = showAddr||interact;
      edit = edit&&interact;
   }
   if( argLast!=argc )
      if( (fd=open(argv[argIdx],(edit?O_RDWR:O_RDONLY)|DOS_BINARY))<0 ) {
         fprintf(stderr,"%s: Can't open file \"%s\"",p,argv[argIdx]);
         if( edit )
            fprintf(stderr," for reading and writing");
         fprintf(stderr,".\n");
         exit(1);
      }
   if( ln )
      bk = ln*rw;
   else
      setWidth(s);
   delta = inc?delta:bk;
   if( fd!=STDIN )
      efpos = lseek(fd,0,SEEK_END);
   if( noStop ) {
      if( fd==STDIN||efpos<=0 )
         sprintf(h,"%ld",LONG_MAX);
      else
         sprintf(h,"%ld",efpos-1); } 
   else
      #ifdef LONG_ONLY
      sprintf(h,"%lu",stop-1);
      #else
      sprintf(h,"%llu",stop-1);
      #endif
   len = strlen(h);
   len = showAddr?len:0;
   if( fd==STDIN ) {
      #ifdef MSDOS
      /* This should be the function that will provide setting of the mode
         of a file after it has been open -- this might be found in io.h */
      setmode(STDIN,DOS_BINARY);
      #endif
      fpos = 0;
      while( fpos<start&&(cont=(read(fd,&c,1)>0)) )
         ++fpos; }
   else {
      efpos = fpos = start;
      lseek(fd,efpos,SEEK_SET);
   }
   setFormat(s);
   if( (cont=(read(fd,&c,1)>0&&(noStop||fpos<stop)))&&head )
      setHeader(h,oh,1);
   while( cont ) {
      if( (fpos-start)%ln==0 )
         if( showAddr )
            #ifdef LONG_ONLY
            sprintf(line,"%0*lu:",len,fpos);
            #else
            sprintf(line,"%0*llu:",len,fpos);
            #endif
         else
            sprintf(line," ");
      if( showChar||charOnly )
         /* Here is where non-printable characters are excluded.
            Modify according to your system. */
         #ifdef MSDOS
         buffer[i] = c==0||6<c&&c<11||c==13||c==26?'.':c;
         #endif
         #ifdef LINUX_PC
         buffer[i] = c<32||c==127||c==155?'.':c;
         #endif
         #ifndef MSDOS
         #ifndef LINUX_PC
         buffer[i] = c<32||126<c?'.':c;
         #endif
         #endif
      if( !compress&&base )
         strcat(line," ");
      if( base==2 ) {
         for(j=128;j;j/=2)
         strcat(line,(c&j)!=0?"1":"0"); }
      else {
         sprintf(s,fs,c);
         strcat(line,s);
      }
      ++fpos; ++i;
      if( i==ln ) {
         i = finishLine(line,buffer,i);
         if( !interact||head||(fpos-start)!=bk )
            printf("\n");
      }
      if( (fpos-start)==bk ) {
         if( head ) {
            printf("%s",h);
            if( !interact )
               printf("\n");
         }
         if( interact )
            cmd = command(fd);
         if( (!interact||!cmd)&&delta!=bk ) {
            if( delta<0&&-delta>start )
               start = 0;
            else if( start+delta>LONG_MAX ) {
               inc = 0;
               delta = bk;
               start = LONG_MAX; }
            else
               start += delta;
            efpos = fpos = start;
            if( lseek(fd,efpos,SEEK_SET)<0 ) {
               fprintf(stderr,"%s: An error has occurred while attempting",p);
               fprintf(stderr," to\n%*s  position in file ",strlen(p),"");
               fprintf(stderr,"stream.  This may be corrected\n");
               fprintf(stderr,"%*s  by either adjusting or ",strlen(p),"");
               fprintf(stderr,"removing the -i option.\n");
               exit(1);
            }
         }
         start = fpos;
         ofpos = mfpos;
      }
      if( interact&&fpos>LONG_MAX ) {
         if( i )
            finishLine(line,buffer,i);
         printf("\n<< Browsing limit: Use a non-interactive mode to ");
         printf("see more of this file. >>\n");
         exit(0);
      }
      cont = cnt&&read(fd,&c,1)>0&&(noStop||fpos<stop);
   }
   close(fd);
   if( cnt&&i ) {
      finishLine(line,buffer,i);
      printf("\n");
   }
   return 0;
}

short command(int fd)
{
   short stay, cl, bad;
   unsigned char value;
   #ifdef LONG_ONLY
   unsigned long num;
   long inum;
   #else
   unsigned long long num;
   long long inum;
   #endif
   char *tp, *ttp, *stp, *sp;
   static char s[2048], t[2048], sc[2];

   sc[1] = '\0';
   printf(" ");
   while( !fgets(s,2048,stdin) ); sp = s;
   clrInput(sp,1);
   if( *s=='<' ) {
      ++sp;
      mfpos = start;
   }
   if( *sp ) {
      sc[0] = *sp;
      if( cnt=(*sp!='Q'&&*sp!='q') ) {
         stay = 1;
         if( *sp=='+'&&!sp[1] ) {
            stay = inc = 0;
            delta = bk; }
         else if( *sp=='>'&&!sp[1] )
            start = ofpos;
         else if( *sp=='*'&&sp[1]&&isNum(sp+1,0) ) {
            num = strtol(sp+1,(char**)NULL,10);
            inum = inc?delta:bk;
            if( inum<0&&-inum*num>start )
               num = 0;
            else
               num = start+inum*num;
            start = num; }
         else if( *sp=='/'&&!sp[1] ) {
            if( head=!head )
               setHeader(h,oh,1); }
         else if( *sp=='|'&&!sp[1] ) {
            showChar = !showChar;
            if( head )
               setHeader(h,oh,0); }
         else if( *sp=='+'&&sp[1]&&isNum(sp+1,0) ) {
            start += delta = strtol(sp+1,(char**)NULL,10);
            inc = 1; }
         else if( *sp=='-'&&!sp[1] ) {
            delta = -(inc?delta:bk);
            inc = 1;
            if( delta<0&&-delta>start )
               start = 0;
            else
               start += delta; }
         else if( *sp=='-'&&sp[1]&&isNum(sp+1,0) ) {
            delta = -strtol(sp+1,(char**)NULL,10);
            inc = 1;
            if( delta<0&&-delta>start )
               start = 0;
            else
               start += delta; }
         else if( *sp=='?'&&!sp[1] ) {
            listCmds1(edit);
            contin("");
            listCmds2();
            contin("");
            if( head )
               printf("%s\n",h); }
         else if( *sp=='#'&&!sp[1] ) {
            printf("INC = ");
            if( inc )
               printf("%ld ",delta);
            printf("%sdefault%s%ld)",inc?"(":"",inc?": ":" (",bk);
            contin(" ");
            if( head )
               printf("%s\n",h); }
         else if( *sp=='!'&&!sp[1] ) {
            compress = !compress;
            if( head )
               setHeader(h,oh,0); }
         else if( strstr("BbCcDdHhOo",sc)&&
          (!sp[1]||sp[1]=='.'&&isNum(sp+2,0)) ) {
            if( sp[1]=='.'||!usrWidth ) {
               usrWidth = 0;
               if( sp[1]=='.'&&(cl=atoi(sp+2))>0 ) {
                  usrWidth = 1;
                  ln = cl>128?128:cl;
                  bk = rw*ln; }
               else
                  setWidth(sc);
               delta = inc?delta:bk;
            }
            setFormat(sc);
            if( head )
               setHeader(h,oh,0); }
         else if( tp=isNum(sp,1) ) {
            if( (cl=atoi(tp+1))>0 ) {
               ln = cl>128?128:cl;
               usrWidth = 1;
               if( head )
                  setHeader(h,oh,0);
            }
            if( (rl=atoi(sp))>0 )
               rw = rl>64?64:rl;
            bk = rw*ln;
            delta = inc?delta:bk; }
         else if( edit&&*sp=='@'&&sp[1]&&isNum(sp+1,0) ) {
            efpos = strtol(sp+1,(char**)NULL,10);
            lseek(fd,efpos,SEEK_SET);
            if( read(fd,&value,1)>0 ) {
               lseek(fd,-1,SEEK_CUR);
               tp = numerals+22-base-(base==16?6:0);
               *t = '@';
               while( *t&&read(fd,&value,1)>0 ) {
                  printf("%0*ld:%s",len,efpos,!base?"  ":compress?"":" ");
                  while( !fgets(t,2048,stdin) ); stp = t;
                  bad = clrInput(t,base);
                  if( *t ) {
                     if( bad ) {
                        lseek(fd,-1,SEEK_CUR);
                        printf("Invalid characters in input.\n"); }
                     else if( base ) {
                        lseek(fd,-1,SEEK_CUR);
                        num = 1; ttp = stp;
                        while( num&&*stp )
                           if( *stp==' ' )
                              ++stp;
                           else {
                              sc[0] = *ttp = *stp;
                              num = (strstr(tp,sc)!=NULL);
                              ++ttp; ++stp;
                           }
                        *ttp = '\0';
                        if( !num )
                           printf("Base %d number invalid.\n",base);
                        else if( (num=strtoul(t,(char**)NULL,base))>255 )
                           printf("Value out of range [0..%s].\n",
                            base==2?"11111111":base==8?"377":
                            base==10?"255":"FF");
                        else {
                           value = num;
                           write(fd,&value,1);
                           ++efpos;
                        } }
                     else {
                        do {
                           lseek(fd,-1,SEEK_CUR);
                           write(fd,stp,1);
                           ++stp; ++efpos;
                        } while( *stp&&read(fd,&value,1)>0 );
                     }
                  }
               } }
            else
               contin("Offset out of range ");
            if( head )
               printf("%s\n",h); }
         else if( isNum(sp,0) )
            start = strtol(sp,(char**)NULL,10);
         else {
            contin("Unrecognized command ");
            if( head )
               printf("%s\n",h);
         }
         if( stay ) {
            if( start>LONG_MAX )
               start = LONG_MAX;
            efpos = fpos = start;
            lseek(fd,efpos,SEEK_SET);
         }
      }
   }
   return *sp;
}

short finishLine(char* line,char* buffer,short i)
{
   short j;

   printf("%s",line);
   if( showChar||charOnly ) {
      buffer[i] = '\0';
      for(j=i;j<ln;++j)
         printf("%s%s",fill,compress||charOnly?"":" ");
      printf(" |%s|",buffer);
   }
   return 0;
}

void setWidth(char* s)
{
   ln = strstr("BCDHO",s)!=NULL?32:16;
   bk = rw*(ln*=(strstr("Cc",s)!=NULL?4:1));
   bk = rw*(ln/=(strstr("Bb",s)!=NULL?2:1));
}

void setFormat(char* s)
{
   strcpy(hs,"%3d");
   strcpy(fill,"   ");
   charOnly = 0;
   if( strstr("Oo",s) ) {
      base = 8;
      strcpy(fs,"%03o"); }
   else if( strstr("Dd",s) ) {
      base = 10;
      strcpy(fs,"%03u"); }
   else if( strstr("Hh",s) ) {
      base = 16;
      strcpy(fs,"%02X");
      strcpy(hs,"%2d");
      strcpy(fill,"  "); }
   else if( strstr("Bb",s) ) {
      base = 2;
      strcpy(hs,"%8d");
      strcpy(fill,"        "); }
   else if( strstr("Cc",s) ) {
      base = 0;
      charOnly = 1;
      strcpy(fs,"");
      strcpy(hs,"");
      strcpy(fill,"");
   }
}

void setHeader(char* h,char* oh,short print)
{
   unsigned short md = (compress&&base!=2) + (base==16);
   short j;
   char s[10];

   md = md==2?10:md==1?100:128;
   for(j=0;j<len+1;++j)
      h[j] = ' ';
   h[j] = '\0';
   if( strlen(hs) ) {
      for(j=0;j<ln;++j) {
         sprintf(s,hs,j%md);
         if( !compress )
            strcat(h," ");
         strcat(h,s);
      }
      h[len+!compress] = '[';
      if( showChar )
         strcat(h,"  "); }
   else
      strcat(h," [");
   if( showChar||charOnly )
      for(j=0;j<ln;++j) {
         sprintf(s,"%d",j%10);
         strcat(h,s);
      }
   strcat(h,"]");
   if( print||strcmp(oh,h) ) {
      printf("%s\n",h);
      strcpy(oh,h);
   }
}

char* isNum(char* s,short period)
{
   short dot = 0, num = 1;
   char sc[2], *sp = s, *tp = numerals+12;

   sc[1] = '\0';
   while( *s&&num ) {
      sc[0] = *s;
      num = (strstr(tp,sc)!=NULL)||period&&*s=='.'&&!dot;
      if( *s=='.'&&!dot )
         sp = s;
      dot += (*s=='.');
      ++s;
   }
   if( period )
      num = num&&(dot||period==2);
   return num?sp:NULL;
}

short clrInput(char* s,short clrSpaces)
{
   short bad = 0, ncr = 1;
   char *v, *t;
   v = t = s;
   while( *v )
      if( *v<32||126<*v ) {
         ncr = ncr&&(*v!='\n');
         bad = bad||(*v!='\n');
         ++v; }
      else {
         *t = *v;
         ++t; ++v;
      }
   *t = '\0';
   if( clrSpaces ) {
      t = s;
      while( *s )
         if( *s==' ' )
            ++s;
         else {
            *t = *s;
            ++t; ++s;
         }
      *t = '\0';
   }
   if( ncr )
      #ifdef MSDOS
      printf("\n\n");
      #else
      printf("\n");
      #endif
   return bad;
}

void contin(char* s)
{
   static char t[2048];

   printf("%s>> Press Enter to continue: ",s);
   while( !fgets(t,2048,stdin) ); clrInput(t,1);
}

void diff(char** argv,char* p)
{
   short i, j, u, zero;
   int n1, n2;
   #ifdef LONG_ONLY
   unsigned long f1 = 0, f2 = 0;
   #else
   unsigned long long f1 = 0, f2 = 0;
   #endif
   unsigned char c1[8192], c2[8192];
   int fdo;

   if( (fd=open(argv[2],O_RDONLY|DOS_BINARY))<0 ) {
      if( argv[1][0]!='.' )
         fprintf(stderr,"%s: Can't open file \"%s\".\n",p,argv[2]);
      exit(1);
   }
   if( (fdo=open(argv[3],O_RDONLY|DOS_BINARY))<0 ) {
      if( argv[1][0]!='.' )
         fprintf(stderr,"%s: Can't open file \"%s\".\n",p,argv[3]);
      exit(1);
   }
   fs[0] = '\0';
   if( argv[1][0]=='d' ) {
      ln = 3;
      strcpy(fs,"%3u %3u\n"); }
   else if( argv[1][0]=='h' ) {
      ln = 2;
      strcpy(fs,"%2X %2X\n"); }
   else if( argv[1][0]=='o' ) {
      ln = 3;
      strcpy(fs,"%3o %3o\n"); }
   else if( argv[1][0]=='b' )
      ln = 8;
   sprintf(h,"%ld",LONG_MAX);
   len = strlen(h);
   fpos = u = 0;
   f1 += n1 = read(fd,c1,8192);
   f2 += n2 = read(fdo,c2,8192);
   while( n1>0||n2>0 ) {
      for(i=0;i<n1&&i<n2;++i) {
         if( c1[i]!=c2[i] ) {
            u = 2;
            if( ln ) {
               #ifdef LONG_ONLY
               printf("%*lu: ",len,fpos);
               #else
               printf("%*llu: ",len,fpos);
               #endif
               if( *fs )
                  printf(fs,c1[i],c2[i]);
               else {
                  for(j=128,zero=0;j;j/=2) {
                     zero = zero||(c1[i]&j)!=0||j==1;
                     printf("%c",(c1[i]&j)!=0?'1':zero?'0':' ');
                  }
                  printf(" ");
                  for(j=128,zero=0;j;j/=2) {
                     zero = zero||(c2[i]&j)!=0||j==1;
                     printf("%c",(c2[i]&j)!=0?'1':zero?'0':' ');
                  }
                  printf("\n");
               } }
            else
               ++ofpos;
         }
         ++fpos;
      }
      f1 += n1 = read(fd,c1,8192);
      f2 += n2 = read(fdo,c2,8192);
   }
   close(fd);
   close(fdo);
   if( u&&argv[1][0]=='-' )
      #ifdef LONG_ONLY
      printf("%lu byte%s ",ofpos,ofpos==1?"":"s");
      #else
      printf("%llu byte%s ",ofpos,ofpos==1?"":"s");
      #endif
   if( f1!=f2 ) {
      if( ln )
         #ifdef LONG_ONLY
         printf("%*lu:%*sEOF%*s:%lu\n",len,f1,ln,"",ln,"",f2);
         #else
         printf("%*llu:%*sEOF%*s:%llu\n",len,f1,ln,"",ln,"",f2);
         #endif
      else if( argv[1][0]=='-' )
         #ifdef LONG_ONLY
         printf("%sizes %lu and %lu ",u?"and s":"S",f1,f2);
         #else
         printf("%sizes %llu and %llu ",u?"and s":"S",f1,f2);
         #endif
      u = u?4:3;
   }
   if( u&&argv[1][0]=='-' )
      printf("differ%s\n",ofpos==1&&f1==f2?"s":"");
   exit(u);
}

void chng(char** argv,char* p)
{
   unsigned long num;
   unsigned char value;

   if( isNum(argv[2],2) ) {
      start=strtol(argv[2],(char**)NULL,10);
      if( (sp=strstr(argv[2],"."))&&sp[1] ) {
         #ifdef LONG_ONLY
         stop = strtoul(sp+1,(char**)NULL,10);
         #else
         stop = strtoull(sp+1,(char**)NULL,10);
         #endif
         noStop = 0;
      } }
   else
      usage(p,1);
   if( !isNum(argv[3],0)||(num=strtoul(argv[3],(char**)NULL,10))>255 )
      usage(p,1);
   value = num;
   if( (fd=open(argv[4],O_RDWR|DOS_BINARY))<0 ) {
      fprintf(stderr,"%s: Can't open file \"%s\" for reading and writing.\n",
       p,argv[4]);
      exit(1);
   }
   efpos = start;
   lseek(fd,efpos,SEEK_SET);
   while( read(fd,&c,1)>0&&(noStop||efpos<stop) ) {
      lseek(fd,-1,SEEK_CUR);
      write(fd,&value,1);
      ++efpos;
   }
   close(fd);
   exit(0);
}

void move(int argc,char** argv,char* p)
{
   long ffpos;
   int fdo;

   if( isNum(argv[2],2) ) {
      start=strtol(argv[2],(char**)NULL,10);
      if( (sp=strstr(argv[2],"."))&&sp[1] ) {
         #ifdef LONG_ONLY
         stop = strtoul(sp+1,(char**)NULL,10);
         #else
         stop = strtoull(sp+1,(char**)NULL,10);
         #endif
         noStop = 0;
      } }
   else
      usage(p,1);
   if( (fd=open(argv[3],O_RDONLY|DOS_BINARY))<0 ) {
      fprintf(stderr,"%s: Can't open file \"%s\".\n",p,argv[3]);
      exit(1);
   }
   #ifdef MSDOS
   if( (fdo=open(argv[argc-1],O_RDWR|O_CREAT|DOS_BINARY,
    S_IREAD|S_IWRITE))<0 ) {
   #else
   if( (fdo=open(argv[argc-1],O_RDWR|O_CREAT|DOS_BINARY,
    S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH))<0 ) {
   #endif
      fprintf(stderr,"%s: Can't open file \"%s\" for reading and writing.\n",
       p,argv[argc-1]);
      exit(1);
   }
   efpos = 0;
   if( argv[1][0]=='a' ) {
      lseek(fdo,0,SEEK_END);
      if( read(fdo,&c,1)>0 ) {
         fprintf(stderr,"%s: Cannot append to file \"%s\".\n",p,argv[argc-1]);
         exit(1);
      }
      efpos = lseek(fd,0,SEEK_END);
      if( read(fd,&c,1)>0 ) {
         fprintf(stderr,"%s: Cannot append from file \"%s\".\n",p,argv[3]);
         exit(1);
      }
   }
   ffpos = fpos = start;
   lseek(fd,ffpos,SEEK_SET);
   ffpos = 0;
   while( read(fd,&c,1)>0&&(noStop||fpos<stop)&&
    (argv[1][0]=='c'||fpos<efpos) ) {
      write(fdo,&c,1);
      ++fpos; ++ffpos;
   }
   close(fd);
   if( argv[1][0]=='c' )
      #ifdef BORLAND
      chsize(fdo,ffpos);
      #else
      ftruncate(fdo,ffpos);
      #endif
   close(fdo);
   exit(0);
}

void tran(int argc,char** argv,char* p,char cb,unsigned short S)
{
   unsigned short maxLen, i = 0, j, digit, digits = 0, cmnts = 0;
   unsigned long num;
   unsigned char b;
   char *tp, sc[2], buf[8192];
   int n1, n2;
   int fdo;

   sc[1] = '\0';
   if( !S )
      if( (fd=open(argv[3],O_RDONLY|DOS_BINARY))<0 ) {
         fprintf(stderr,"%s: Can't open file \"%s\".\n",p,argv[3]);
         exit(1);
      }
   #ifdef MSDOS
   if( (fdo=open(argv[argc-1],O_WRONLY|O_CREAT|DOS_BINARY,
    S_IREAD|S_IWRITE))<0 ) {
   #else
   if( (fdo=open(argv[argc-1],O_WRONLY|O_CREAT|DOS_BINARY,
    S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH))<0 ) {
   #endif
      fprintf(stderr,"%s: Can't open file \"%s\" for writing.\n",p,
       argv[argc-1]);
      exit(1);
   }
   base = cb=='b'?2:cb=='o'?8:cb=='d'?10:16;
   maxLen = cb=='b'?8:cb=='o'||cb=='d'?3:2;
   tp = numerals+22-base-(base==16?6:0);
   efpos = 0;
   n1 = n2 = read(fd,buf,8192);
   while( n1>0 ) {
      for(j=0;j<n1;++j) {
         if( n1=n2 ) {
            sc[0] = c = buf[j];
            digit = (strstr(tp,sc)!=NULL&&c); }
         else
            digit = 0;
         if( !cmnts ) {
            digits = digits||digit;
            if( digits )
               if( digit&&i<maxLen )
                  fill[i++] = c;
               else {
                  fill[i] = '\0';
                  if( (num=strtoul(fill,(char**)NULL,base))>255 ) {
                     fprintf(stderr,"%s: Value %s out of range [0..%s].\n",p,
                      fill,base==8?"377":"255");
                     exit(1); }
                  else {
                     b = num;
                     write(fdo,&b,1);
                     ++efpos;
                  }
                  i = 0;
                  if( digit )
                     fill[i++] = c;
                  else
                     digits = 0;
               }
	 }
         if( !digit&&(c=='|'||c=='\n') )
            cmnts = (c!='\n'&&(cmnts||c=='|'));
      }
      if( n2>0 )
         n2 = read(fd,buf,8192);
   }
   close(fd);
   #ifdef BORLAND
   chsize(fdo,efpos);
   #else
   ftruncate(fdo,efpos);
   #endif
   close(fdo);
   exit(0);
}

void listCmds1(short showEdCmd)
{
   printf("  +<number>  Set increment INC to <number> and");
   printf(" increment.\n");
   printf("  -<number>  Set increment INC to -<number> and");
   printf(" increment.\n");
   printf("  *<number>  Increment <number> * INC bytes.\n");
   printf("  <Enter>    Increment INC bytes.\n");
   printf("  -          Set INC to -INC and increment.\n");
   printf("  +          Set INC to default (rows * columns) and increment.\n");
   printf("  #          Display current value of INC.\n");
   printf("  <number>   Go to file offset position <number>.\n");
   if( showEdCmd ) {
      printf("  @<number>  Overwrite bytes starting at position <number>. ");
      printf(" (Edit mode only.)\n");
   }
   printf("  b|B        Binary display (default 8|16 columns).\n");
   printf("  d|D        Decimal display (default 16|32 columns).\n");
   printf("  h|H        Hexadecimal display (default 16|32 columns).\n");
   printf("  o|O        Octal display (default 16|32 columns).\n");
   printf("  c|C        Character display only (default 64|128 columns).\n");
}

void listCmds2(void)
{
   printf("  [r].[c]    If r is nonzero, set number of rows to r");
   printf(" (range [1..64]).\n");
   printf("             If c is nonzero, override column defaults of above");
   printf(" alphabetic\n");
   printf("             commands and set number of columns to c");
   printf(" (range [1..128]).\n");
   printf("  A.[c]      Display according to A (=b|B|d|D|h|H|o|O|c|C)");
   printf(" and restore\n");
   printf("             default column settings if c not present or zero; ");
   printf("otherwise,\n");
   printf("             override column defaults and set number of columns ");
   printf("to c.\n");
   printf("  |          Toggle between supplemental character display ");
   printf("present or absent.\n");
   printf("  /          Toggle between column labels or no column labels.\n");
   printf("  !          Toggle between compressed or uncompressed numeric ");
   printf("display.\n");
   printf("  <C         Mark current position and execute command C.\n");
   printf("  >          Go to previous marked position.  (Initial marked");
   printf(" position is 0.)\n");
   printf("  ?          Display this list of commands.\n");
   printf("  Q|q        Terminate program.\n");
}

void usage(char* p,short u)
{
  FILE* fp;

  fp = u==1?stderr:stdout;
  fprintf(fp,"Usage: %s\n  [- c|h|n|v] | [[-AaBbCcDdEeHhKkLlNnOoSsTt]",p);
  fprintf(fp," [-i INC] [-r RNG] [-p PS] File] |\n");
  fprintf(fp,"  [r RNG BYTE File] | [a|c RNG File1 [File2]] | ");
  fprintf(fp,"[t[ ]b|d|h|o File1 [File2]] |\n");
  fprintf(fp,"  [b|d|h|o|-|. File1 File2]\n");
  fprintf(fp,"Enter: %s\n  - h for help, - n for notes, ",p);
  fprintf(fp,"- v for version, or - c for commands.\n");
  if( u<2 )
     exit(u);
}

void info(char** argv,char* p)
{
   if( argv[2][0]=='h' ) {
      usage(p,2);
      help(p);
      exit(0); }
   else if( argv[2][0]=='n' ) {
      printf("+ Program terminates if it reads past the last byte of ");
      printf("the file.\n");
      printf("+ INC is set to default whenever the offset is beyond %ld.\n",
       LONG_MAX);
      printf("+ To prevent skewing of column labels when reading some files ");
      printf("(e.g. a growing\n  file) pass the program ");
      printf("a maximum file size in the argument to the -r option.\n");
      printf("+ Overwriting, command @ (edit mode only), will ");
      printf("accept input according to the\n  current numeric base and ");
      printf("will accept character strings (byte values in the\n  range ");
      printf("[32..126]) when no numeric display is present.\n");
      printf("+ Enter \"<>\" to toggle between two file positions.\n");
      printf("+ Files open for writing are also open for reading (see ");
      printf("exception below).\n");
      printf("+ Translate method: %s t[ ]b|d|h|o File1 [File2]\n",p);
      printf("  - All characters from \"|\" to end of line are ignored for ");
      printf("input lines.\n");
      printf("  - If File1 and File2 are not the same file, File2 is open ");
      printf("for writing only.\n");
      printf("  - Numbers in input may be delimited by any non-digit ");
      printf("for base 2|8|10|16 with\n");
      printf("    the exception of the \"|\" character.  If not delimited, ");
      printf("8|3|3|2 digits will\n");
      printf("    be converted at a time.\n");
      printf("  - Example: %s -als File | %s th File.out\n",p,p);
      printf("    results in File and File.out having identical ");
      printf("contents.\n");
      exit(0); }
   else if( argv[2][0]=='v' ) {
      #ifdef MSDOS
      printf("FB");
      #else
      printf("fb");
      #endif
      printf(" - File Browser, version 1.5, 2 May 1999\n");
      printf("     Copyright (C) 1998, 1999 John Howard Swaby\n");
      printf("     Report bugs to polymath@uwyo.edu\n");
      #ifdef MSDOS
      if( strcmp(p,"FB") )
      #else
      if( strcmp(p,"fb") )
      #endif
         printf("Current alias: %s\n",p);
      exit(0); }
   else if( argv[2][0]=='c' ) {
      listCmds1(1); listCmds2();
      exit(0);
   }
}

void help(char* p)
{
   printf("Base options:\n");
   printf(" -b,-B    Binary numbers (8 or 16 columns).\n");
   printf(" -d,-D    Decimal numbers (16 or 32 columns).\n");
   printf(" -h,-H    Hexadecimal numbers (16 or 32 columns).\n");
   printf(" -o,-O    Octal numbers (16 or 32 columns).\n");
   printf("Display options:\n");
   printf(" -a,-A    Suppress or display offset addresses.\n");
   printf("          (Option -a is ignored if effective mode is ");
   printf("interactive.)\n");
   printf(" -c,-C    Characters only (64 or 128 columns).\n");
   printf(" -k,-K    Compressed or uncompressed numeric display.\n");
   printf(" -l,-L    Suppress or display column labels.\n");
   printf(" -n,-N    Exclude or include supplemental character display.\n");
   printf("Mode options:\n");
   printf(" -e       Edit mode.  (Ignored if either -s or -t options ");
   printf("in effect.)\n");
   printf(" -E       Read-only mode.\n");
   printf(" -s       Stream output (non-interactive mode).\n");
   printf(" -S       Interactive mode.  (Will nullify previous -s or -t ");
   printf("options.)\n");
   printf(" -t       Read from standard input and stream output ");
   printf("(non-interactive mode).\n");
   printf("          (Will nullify previous -S or -T options.)  ");
   printf("File name MUST be \"-\".\n");
   printf(" -T       Read from File.\n");
   printf("Options with arguments:\n");
   printf(" -i INC   Increment page INC bytes [0..%ld].\n",LONG_MAX);
   printf("          0 sets increment to default, (number of rows)*");
   printf("(number of columns).\n");
   printf(" -r RNG   Portion of File to browse.  RNG is Start | ");
   printf("[Start].[Stop];\n");
   printf("          where Start [0..%ld] (default: 0) and Stop ",LONG_MAX);
   printf("(default:\n");
   printf("          end of file) are the starting and stopping offsets ");
   printf("of File.\n");
   printf(" -p PS    Page size.  PS is Rw | [Rw].[Cl].  Rw [0..64] is ");
   printf("number of rows\n");
   printf("          (default: 16).  Cl [0..128] is number of columns ");
   printf("(default: specified\n");
   printf("          by either the base option or ");
   printf("-c,-C options).  0 for either Rw or Cl\n");
   printf("          will also invoke their defaults.\n");
   printf("Note: Options are evaluated left-to-right.  When options\n");
   printf("      are mutually exclusive, only last one is effective.\n");
   printf("      \"%s File\" performs the same as\n",p);
   printf("      \"%s -hAEKLNST -p . -r . -i 0 File\".",p);
   printf("\n");
   printf("Replace method: %s r RNG BYTE File\n",p);
   printf("  Replace bytes in range RNG of File with value BYTE ");
   printf("[0..255].  RNG is\n  Start | [Start].[Stop]; where Start ");
   printf("(default: 0) is offset in File where\n  replacement should ");
   printf("start and Stop (default: end of file) is offset where\n");
   printf("  replacement should stop.\n");
   printf("Append/Copy method: %s a|c RNG File1 [File2]\n",p);
   printf("  Copy bytes in range RNG from File1 and append|copy to ");
   printf("File1 or optional\n");
   printf("  File2.  RNG is Start | [Start].[Stop]; where Start (default: 0)");
   printf(" is offset\n  in File1 where copying should start and Stop ");
   printf("(default: end of file) is\n  offset where copying should ");
   printf("stop.\n");
   printf("Translate method: %s t[ ]b|d|h|o File1 [File2]\n",p);
   printf("  Convert binary|decimal|hexadecimal|octal numbers in File1 ");
   printf("(or standard input\n  if space is absent between \"t\" and base ");
   printf("indicator) into bytes and copy bytes\n  to File1 (or optional ");
   printf("File2 if input is NOT from standard input).  See under\n");
   printf("  notes (%s - n) for more information.\n",p);
   printf("Compare method: %s b|d|h|o|-|. File1 File2\n",p);
   printf("  Report offsets and byte values (in binary|decimal|hexadecimal|");
   printf("octal) where\n  File1 and File2 differ till end of shortest file.");
   printf("  If file lengths differ,\n  report end of file (EOF) for both ");
   printf("files.  \"-\" - report only if files differ\n  and how.  \".\" - ");
   printf("return exit status only: 0 - files the same, 1 - error,\n  ");
   printf("2 - bytes differ, 3 - sizes differ, 4 - bytes and sizes differ.\n");
}

/* end of file: fb.c */