4.3BSD - /usr/src/bin/diff/diffh.c

   1: static  char sccsid[] = "@(#)diffh.c 4.4 11/27/85";
   2: 
   3: #include <stdio.h>
   4: #include <ctype.h>
   5: #include <sys/types.h>
   6: #include <sys/stat.h>
   7: 
   8: #define C 3
   9: #define RANGE 30
  10: #define LEN 255
  11: #define INF 16384
  12: 
  13: char *text[2][RANGE];
  14: long lineno[2] = {1, 1};    /*no. of 1st stored line in each file*/
  15: int ntext[2];       /*number of stored lines in each*/
  16: long n0,n1;     /*scan pointer in each*/
  17: int bflag;
  18: int debug = 0;
  19: FILE *file[2];
  20: 
  21:     /* return pointer to line n of file f*/
  22: char *getl(f,n)
  23: long n;
  24: {
  25:     register char *t;
  26:     char *malloc();
  27:     register delta, nt;
  28: again:
  29:     delta = n - lineno[f];
  30:     nt = ntext[f];
  31:     if(delta<0)
  32:         progerr("1");
  33:     if(delta<nt)
  34:         return(text[f][delta]);
  35:     if(delta>nt)
  36:         progerr("2");
  37:     if(nt>=RANGE)
  38:         progerr("3");
  39:     if(feof(file[f]))
  40:         return(NULL);
  41:     t = text[f][nt];
  42:     if(t==0) {
  43:         t = text[f][nt] = malloc(LEN+1);
  44:         if(t==NULL)
  45:             if(hardsynch())
  46:                 goto again;
  47:             else
  48:                 progerr("5");
  49:     }
  50:     t = fgets(t,LEN,file[f]);
  51:     if(t!=NULL)
  52:         ntext[f]++;
  53:     return(t);
  54: }
  55: 
  56:     /*remove thru line n of file f from storage*/
  57: clrl(f,n)
  58: long n;
  59: {
  60:     register i,j;
  61:     j = n-lineno[f]+1;
  62:     for(i=0;i+j<ntext[f];i++)
  63:         movstr(text[f][i+j],text[f][i]);
  64:     lineno[f] = n+1;
  65:     ntext[f] -= j;
  66: }
  67: 
  68: movstr(s,t)
  69: register char *s, *t;
  70: {
  71:     while(*t++= *s++)
  72:         continue;
  73: }
  74: 
  75: main(argc,argv)
  76: char **argv;
  77: {
  78:     char *s0,*s1;
  79:     FILE *dopen();
  80:     register int status = 0;
  81: 
  82:     while(*argv[1]=='-') {
  83:         argc--;
  84:         argv++;
  85:         while(*++argv[0])
  86:             if(*argv[0]=='b')
  87:                 bflag++;
  88:     }
  89:     if(argc!=3)
  90:         error("must have 2 file arguments","");
  91:     file[0] = dopen(argv[1],argv[2]);
  92:     file[1] = dopen(argv[2],argv[1]);
  93:     for(;;) {
  94:         s0 = getl(0,++n0);
  95:         s1 = getl(1,++n1);
  96:         if(s0==NULL||s1==NULL)
  97:             break;
  98:         if(cmp(s0,s1)!=0) {
  99:             if(!easysynch()&&!hardsynch())
 100:                 progerr("5");
 101:             status = 1;
 102:         } else {
 103:             clrl(0,n0);
 104:             clrl(1,n1);
 105:         }
 106:     }
 107:     if(s0==NULL&&s1==NULL)
 108:         exit(status);
 109:     if(s0==NULL)
 110:         output(-1,INF);
 111:     if(s1==NULL)
 112:         output(INF,-1);
 113:     exit(1);
 114: }
 115: 
 116:     /* synch on C successive matches*/
 117: easysynch()
 118: {
 119:     int i,j;
 120:     register k,m;
 121:     char *s0,*s1;
 122:     for(i=j=1;i<RANGE&&j<RANGE;i++,j++) {
 123:         s0 = getl(0,n0+i);
 124:         if(s0==NULL)
 125:             return(output(INF,INF));
 126:         for(k=C-1;k<j;k++) {
 127:             for(m=0;m<C;m++)
 128:                 if(cmp(getl(0,n0+i-m),
 129:                     getl(1,n1+k-m))!=0)
 130:                     goto cont1;
 131:             return(output(i-C,k-C));
 132: cont1:          ;
 133:         }
 134:         s1 = getl(1,n1+j);
 135:         if(s1==NULL)
 136:             return(output(INF,INF));
 137:         for(k=C-1;k<=i;k++) {
 138:             for(m=0;m<C;m++)
 139:                 if(cmp(getl(0,n0+k-m),
 140:                     getl(1,n1+j-m))!=0)
 141:                     goto cont2;
 142:             return(output(k-C,j-C));
 143: cont2:          ;
 144:         }
 145:     }
 146:     return(0);
 147: }
 148: 
 149: output(a,b)
 150: {
 151:     register i;
 152:     char *s;
 153:     if(a<0)
 154:         change(n0-1,0,n1,b,"a");
 155:     else if(b<0)
 156:         change(n0,a,n1-1,0,"d");
 157:     else
 158:         change(n0,a,n1,b,"c");
 159:     for(i=0;i<=a;i++) {
 160:         s = getl(0,n0+i);
 161:         if(s==NULL)
 162:             break;
 163:         printf("< %s",s);
 164:         clrl(0,n0+i);
 165:     }
 166:     n0 += i-1;
 167:     if(a>=0&&b>=0)
 168:         printf("---\n");
 169:     for(i=0;i<=b;i++) {
 170:         s = getl(1,n1+i);
 171:         if(s==NULL)
 172:             break;
 173:         printf("> %s",s);
 174:         clrl(1,n1+i);
 175:     }
 176:     n1 += i-1;
 177:     return(1);
 178: }
 179: 
 180: change(a,b,c,d,s)
 181: long a,c;
 182: char *s;
 183: {
 184:     range(a,b);
 185:     printf("%s",s);
 186:     range(c,d);
 187:     printf("\n");
 188: }
 189: 
 190: range(a,b)
 191: long a;
 192: {
 193:     if(b==INF)
 194:         printf("%ld,$",a);
 195:     else if(b==0)
 196:         printf("%ld",a);
 197:     else
 198:         printf("%ld,%ld",a,a+b);
 199: }
 200: 
 201: cmp(s,t)
 202: char *s,*t;
 203: {
 204:     if(debug)
 205:         printf("%s:%s\n",s,t);
 206:     for(;;){
 207:         if(bflag&&isspace(*s)&&isspace(*t)) {
 208:             while(isspace(*++s)) ;
 209:             while(isspace(*++t)) ;
 210:         }
 211:         if(*s!=*t||*s==0)
 212:             break;
 213:         s++;
 214:         t++;
 215:     }
 216:     return(*s-*t);
 217: }
 218: 
 219: FILE *dopen(f1,f2)
 220: char *f1,*f2;
 221: {
 222:     FILE *f;
 223:     char b[100],*bptr,*eptr;
 224:     struct stat statbuf;
 225:     if(cmp(f1,"-")==0)
 226:         if(cmp(f2,"-")==0)
 227:             error("can't do - -","");
 228:         else
 229:             return(stdin);
 230:     if(stat(f1,&statbuf)==-1)
 231:         error("can't access ",f1);
 232:     if((statbuf.st_mode&S_IFMT)==S_IFDIR) {
 233:         for(bptr=b;*bptr= *f1++;bptr++) ;
 234:         *bptr++ = '/';
 235:         for(eptr=f2;*eptr;eptr++)
 236:             if(*eptr=='/'&&eptr[1]!=0&&eptr[1]!='/')
 237:                 f2 = eptr+1;
 238:         while(*bptr++= *f2++) ;
 239:         f1 = b;
 240:     }
 241:     f = fopen(f1,"r");
 242:     if(f==NULL)
 243:         error("can't open",f1);
 244:     return(f);
 245: }
 246: 
 247: 
 248: progerr(s)
 249: char *s;
 250: {
 251:     error("program error ",s);
 252: }
 253: 
 254: error(s,t)
 255: char *s,*t;
 256: {
 257:     fprintf(stderr,"diffh: %s%s\n",s,t);
 258:     exit(2);
 259: }
 260: 
 261:     /*stub for resychronization beyond limits of text buf*/
 262: hardsynch()
 263: {
 264:     change(n0,INF,n1,INF,"c");
 265:     printf("---change record omitted\n");
 266:     error("can't resynchronize","");
 267:     return(0);
 268: }

Defined functions

Defined variables

Defined macros