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