2.9BSD - /usr/src/cmd/diff/diffh.c

   1: static  char sccsid[] = "@(#)diffh.c 4.1 10/9/80";
   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:     extern char _sobuf[];
  81:     setbuf(stdout, _sobuf);
  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:         } else {
 102:             clrl(0,n0);
 103:             clrl(1,n1);
 104:         }
 105:     }
 106:     if(s0==NULL&&s1==NULL)
 107:         return;
 108:     if(s0==NULL)
 109:         output(-1,INF);
 110:     if(s1==NULL)
 111:         output(INF,-1);
 112: }
 113: 
 114:     /* synch on C successive matches*/
 115: easysynch()
 116: {
 117:     int i,j;
 118:     register k,m;
 119:     char *s0,*s1;
 120:     for(i=j=1;i<RANGE&&j<RANGE;i++,j++) {
 121:         s0 = getl(0,n0+i);
 122:         if(s0==NULL)
 123:             return(output(INF,INF));
 124:         for(k=C-1;k<j;k++) {
 125:             for(m=0;m<C;m++)
 126:                 if(cmp(getl(0,n0+i-m),
 127:                     getl(1,n1+k-m))!=0)
 128:                     goto cont1;
 129:             return(output(i-C,k-C));
 130: cont1:          ;
 131:         }
 132:         s1 = getl(1,n1+j);
 133:         if(s1==NULL)
 134:             return(output(INF,INF));
 135:         for(k=C-1;k<=i;k++) {
 136:             for(m=0;m<C;m++)
 137:                 if(cmp(getl(0,n0+k-m),
 138:                     getl(1,n1+j-m))!=0)
 139:                     goto cont2;
 140:             return(output(k-C,j-C));
 141: cont2:          ;
 142:         }
 143:     }
 144:     return(0);
 145: }
 146: 
 147: output(a,b)
 148: {
 149:     register i;
 150:     char *s;
 151:     if(a<0)
 152:         change(n0-1,0,n1,b,"a");
 153:     else if(b<0)
 154:         change(n0,a,n1-1,0,"d");
 155:     else
 156:         change(n0,a,n1,b,"c");
 157:     for(i=0;i<=a;i++) {
 158:         s = getl(0,n0+i);
 159:         if(s==NULL)
 160:             break;
 161:         printf("< %s",s);
 162:         clrl(0,n0+i);
 163:     }
 164:     n0 += i-1;
 165:     if(a>=0&&b>=0)
 166:         printf("---\n");
 167:     for(i=0;i<=b;i++) {
 168:         s = getl(1,n1+i);
 169:         if(s==NULL)
 170:             break;
 171:         printf("> %s",s);
 172:         clrl(1,n1+i);
 173:     }
 174:     n1 += i-1;
 175:     return(1);
 176: }
 177: 
 178: change(a,b,c,d,s)
 179: long a,c;
 180: char *s;
 181: {
 182:     range(a,b);
 183:     printf("%s",s);
 184:     range(c,d);
 185:     printf("\n");
 186: }
 187: 
 188: range(a,b)
 189: long a;
 190: {
 191:     if(b==INF)
 192:         printf("%ld,$",a);
 193:     else if(b==0)
 194:         printf("%ld",a);
 195:     else
 196:         printf("%ld,%ld",a,a+b);
 197: }
 198: 
 199: cmp(s,t)
 200: char *s,*t;
 201: {
 202:     if(debug)
 203:         printf("%s:%s\n",s,t);
 204:     for(;;){
 205:         if(bflag&&isspace(*s)&&isspace(*t)) {
 206:             while(isspace(*++s)) ;
 207:             while(isspace(*++t)) ;
 208:         }
 209:         if(*s!=*t||*s==0)
 210:             break;
 211:         s++;
 212:         t++;
 213:     }
 214:     return(*s-*t);
 215: }
 216: 
 217: FILE *dopen(f1,f2)
 218: char *f1,*f2;
 219: {
 220:     FILE *f;
 221:     char b[100],*bptr,*eptr;
 222:     struct stat statbuf;
 223:     if(cmp(f1,"-")==0)
 224:         if(cmp(f2,"-")==0)
 225:             error("can't do - -","");
 226:         else
 227:             return(stdin);
 228:     if(stat(f1,&statbuf)==-1)
 229:         error("can't access ",f1);
 230:     if((statbuf.st_mode&S_IFMT)==S_IFDIR) {
 231:         for(bptr=b;*bptr= *f1++;bptr++) ;
 232:         *bptr++ = '/';
 233:         for(eptr=f2;*eptr;eptr++)
 234:             if(*eptr=='/'&&eptr[1]!=0&&eptr[1]!='/')
 235:                 f2 = eptr+1;
 236:         while(*bptr++= *f2++) ;
 237:         f1 = b;
 238:     }
 239:     f = fopen(f1,"r");
 240:     if(f==NULL)
 241:         error("can't open",f1);
 242:     return(f);
 243: }
 244: 
 245: 
 246: progerr(s)
 247: char *s;
 248: {
 249:     error("program error ",s);
 250: }
 251: 
 252: error(s,t)
 253: char *s,*t;
 254: {
 255:     fprintf(stderr,"diffh: %s%s\n",s,t);
 256:     exit(1);
 257: }
 258: 
 259:     /*stub for resychronization beyond limits of text buf*/
 260: hardsynch()
 261: {
 262:     change(n0,INF,n1,INF,"c");
 263:     printf("---change record omitted\n");
 264:     error("can't resynchronize","");
 265:     return(0);
 266: }

Defined functions

Defined variables

Defined macros