1 #ifndef lint 2 static char sccsid[] = "@(#)locate.c 2.7 05/27/93"; 3 #endif not lint 4 # 5 6 # include "stdio.h" 7 # include "streams.h" 8 # include "ctype.h" 9 # define maxrefs 1000 10 11 struct reftype{ 12 char reffile[maxstr]; 13 long int start, length; 14 }; 15 16 char *calloc(); 17 char *rindex(); 18 char *stripkeys(); 19 int fetchref(); 20 21 /* locate(keys, name, max_klen, common): 22 Returns a string containing all references pointed to by name 23 that contain all keys in keys. Common is name of common word file. 24 Pointer returned comes from calloc. Use free to return storage. 25 NB A zero length string returned if nothing is found. 26 A NULL pointer indicates an error accessing the file "name". 27 */ 28 int fflag; /* set if want the reference string to have the file name*/ 29 char *locate(keys,name,max_klen,common) 30 char *keys, *name, *common; 31 int max_klen; /* max key length */ 32 { static char oldname[maxstr] = ""; /* oldname is name of stream index */ 33 static FILE *index = NULL; 34 static long int i_size; /* size of index */ 35 static char oldtext[maxstr]; /* oldtext is the path to stream */ 36 static FILE *text = NULL; /* text. if it is a relative */ 37 static int pathlen; /* path, it is relative to index */ 38 /* directory. */ 39 /* oldname[0..pathlen-1] is index */ 40 /* directory */ 41 int len; 42 char key[maxstr]; /* refs[i] is a line of index for */ 43 struct reftype refs[maxrefs]; /* all keys up to key */ 44 45 int refcnt, copied, comp; /* refcnt = # of refs */ 46 /* copied = # of refs copied */ 47 /* comp = # of refs compared */ 48 struct reftype ref; 49 char str[maxstr]; 50 int more; 51 52 long int ans; 53 int i,j; 54 unsigned total; 55 char *allrefs, *next; /* all refs (separated by null line)*/ 56 char *p; 57 58 /* open index */ 59 if (strcmp(oldname,name)!=0) 60 { if (index) fclose(index); 61 if (text) fclose(text); 62 strcpy(oldname,name); 63 strcpy(oldtext,""); 64 /* determine pathlen */ 65 p= rindex(oldname, '/'); 66 if (p!=NULL) pathlen= p-oldname+1; 67 else pathlen= 0; 68 69 index= fopen(oldname,"r"); 70 if (index==NULL) { 71 fprintf(stderr,"locate: cannot open %s\n", oldname); 72 strcpy(oldname, ""); 73 return(NULL); 74 } 75 else { 76 fseek(index,0L,2); /* seeks last newline */ 77 i_size= ftell(index); 78 } 79 80 } 81 82 /* load references to first key */ 83 keys= stripkeys(keys,key, max_klen, common); 84 if (*key==NULL) { 85 fprintf(stderr,"locate: no keys for citation: %s\n", keys); 86 allrefs = (char *) calloc(1, sizeof (char)); 87 if (allrefs==NULL) { 88 fprintf(stderr,"locate: insufficient space for references\n"); 89 exit(1); 90 } 91 *allrefs= NULL; 92 return(allrefs); 93 } 94 len= strlen(key); 95 strcat(key," "); 96 alpha_seek(index, key, i_size, 0); 97 key[len]= NULL; /* strip blank off */ 98 99 refcnt= 0; 100 fscanf(index,"%s ", str); 101 if (strcmp(str,key) == 0) 102 { str[0]= NULL; 103 while (refcnt < maxrefs && fetchref(index, str, &ref) ) 104 { refs[refcnt]= ref; 105 refcnt++; 106 } 107 } 108 109 if (refcnt==maxrefs) 110 fprintf(stderr, 111 "locate: first key (%s) matched too many refs\n", key); 112 113 /* intersect the reference sets for remaining keys with first set */ 114 while (*keys!=NULL) 115 { keys= stripkeys(keys, key, max_klen, common); 116 if (*key==NULL) continue; 117 118 len= strlen(key); 119 strcat(key," "); 120 alpha_seek(index, key, i_size, 0); 121 key[len]= NULL; 122 123 fscanf(index,"%s ", str); 124 if (strcmp(str,key) != 0) refcnt= 0; /* no matching refs */ 125 126 copied= 0; comp= 0; more= fetchref(index, str, &ref); 127 while (comp < refcnt && more) 128 { /* ans= ref-refs[comp] */ 129 ans= strcmp(ref.reffile, refs[comp].reffile); 130 if (ans==0) ans= ref.start-refs[comp].start; 131 if (ans==0) ans= ref.length-refs[comp].length; 132 if (ans<0) more= fetchref(index, str, &ref); 133 if (ans==0) { refs[copied]= refs[comp]; comp++; copied++; 134 more= fetchref(index, str, &ref);} 135 if (ans>0) comp++; 136 } 137 138 refcnt= copied; 139 } 140 141 total= 0; 142 for (i=0; i<refcnt; i++) { 143 total += refs[i].length+1; 144 if (fflag){ 145 total += strlen(refs[i].reffile) + 1; 146 } 147 } 148 149 allrefs= (char *) calloc(total+1, sizeof (char)); 150 if (allrefs==NULL) 151 { fprintf(stderr,"locate: insufficient space for references\n"); 152 exit(1); 153 } 154 155 /* copy refs into allrefs */ 156 next= allrefs; 157 for (i=0; i<refcnt; i++) 158 { /* open text */ 159 if (strcmp(oldtext,refs[i].reffile) != 0) 160 { strcpy(oldtext,refs[i].reffile); 161 if (oldtext[0]=='/') 162 { /* absolute path */ 163 strcpy(str,oldtext); 164 } else 165 { /* relative name */ 166 strncpy(str, oldname, pathlen); str[pathlen]= NULL; 167 strcat(str, oldtext); 168 } 169 if (text) fclose(text); 170 text= fopen(str, "r"); 171 if (text==NULL) 172 { fprintf(stderr,"locate: cannot open %s\n", str); 173 strcpy(oldtext, ""); 174 return(NULL); 175 } 176 } 177 fseek(text, refs[i].start, 0); 178 if (fflag){ 179 strcat(next, refs[i].reffile); 180 next += strlen(next); 181 *next++ = '\n'; 182 *next = 0; 183 } 184 for (j=0; j<refs[i].length; j++) *next++ = getc(text); 185 *next++ = '\n'; 186 } 187 *next = NULL; 188 return(allrefs); 189 } 190 191 192 193 /* stripkeys(line,key,max_klen, common): 194 assigns to key the first key in line 195 and returns a pointer to the position following the key 196 */ 197 char *stripkeys(line,key,max_klen,common) 198 char *line, *key; 199 int max_klen; 200 char *common; 201 { char *p; 202 203 do 204 { while (isspace(*line)) line++; 205 206 p= key; 207 while (*line!=NULL && !isspace(*line)) 208 { *p++ = *line++; 209 } 210 *p= NULL; 211 212 makekey(key, max_klen, common); 213 } while (*key==NULL && *line!=NULL); 214 return(line); 215 } 216 217 /* read a reference pair from stream into *ref. if file not given, 218 use oldfile. return 1 if pair found, 0 ow. 219 */ 220 int fetchref(stream, oldfile, ref) 221 FILE *stream; 222 char *oldfile; 223 struct reftype *ref; 224 { char cntl; 225 226 fscanf(stream, "%c", &cntl); 227 if (cntl=='\n') {return (0);} 228 if (cntl==':') fscanf(stream, "%s", oldfile); 229 strcpy(ref->reffile, oldfile); 230 fscanf(stream, "%D/%D", &ref->start, &ref->length); 231 return(1); 232 } 233