1 /* cut.c - Cut from a file. 2 * 3 * Copyright 2012 Ranjan Kumar <ranjankumar.bth (at) gmail.com> 4 * Copyright 2012 Kyungwan Han <asura321 (at) gmail.com> 5 * 6 * http://pubs.opengroup.org/onlinepubs/9699919799/utilities/cut.html 7 * 8 * TODO: cleanup 9 10 USE_CUT(NEWTOY(cut, "b:|c:|f:|d:sn[!cbf]", TOYFLAG_USR|TOYFLAG_BIN)) 11 12 config CUT 13 bool "cut" 14 default y 15 help 16 usage: cut OPTION... [FILE]... 17 18 Print selected parts of lines from each FILE to standard output. 19 20 -b LIST select only these bytes from LIST. 21 -c LIST select only these characters from LIST. 22 -f LIST select only these fields. 23 -d DELIM use DELIM instead of TAB for field delimiter. 24 -s do not print lines not containing delimiters. 25 -n don't split multibyte characters (Ignored). 26 */ 27 #define FOR_cut 28 #include "toys.h" 29 30 GLOBALS( 31 char *delim; 32 char *flist; 33 char *clist; 34 char *blist; 35 36 void *slist_head; 37 unsigned nelem; 38 void (*do_cut)(int fd); 39 ) 40 41 struct slist { 42 struct slist *next; 43 int start, end; 44 }; 45 46 static void add_to_list(int start, int end) 47 { 48 struct slist *current, *head_ref, *temp1_node; 49 50 head_ref = TT.slist_head; 51 temp1_node = xzalloc(sizeof(struct slist)); 52 temp1_node->start = start; 53 temp1_node->end = end; 54 55 /* Special case for the head end */ 56 if (!head_ref || head_ref->start >= start) { 57 temp1_node->next = head_ref; 58 head_ref = temp1_node; 59 } else { 60 /* Locate the node before the point of insertion */ 61 current = head_ref; 62 while (current->next && current->next->start < temp1_node->start) 63 current = current->next; 64 temp1_node->next = current->next; 65 current->next = temp1_node; 66 } 67 TT.slist_head = head_ref; 68 } 69 70 // parse list and add to slist. 71 static void parse_list(char *list) 72 { 73 for (;;) { 74 char *ctoken = strsep(&list, ","), *dtoken; 75 int start = 0, end = INT_MAX; 76 77 if (!ctoken) break; 78 if (!*ctoken) continue; 79 80 // Get start position. 81 if (*(dtoken = strsep(&ctoken, "-"))) { 82 start = atolx_range(dtoken, 0, INT_MAX); 83 start = (start?(start-1):start); 84 } 85 86 // Get end position. 87 if (!ctoken) end = -1; //case e.g. 1,2,3 88 else if (*ctoken) {//case e.g. N-M 89 end = atolx_range(ctoken, 0, INT_MAX); 90 if (!end) end = INT_MAX; 91 end--; 92 if(end == start) end = -1; 93 } 94 add_to_list(start, end); 95 TT.nelem++; 96 } 97 // if list is missing in command line. 98 if (!TT.nelem) error_exit("missing positions list"); 99 } 100 101 /* 102 * retrive data from the file/s. 103 */ 104 static void get_data(void) 105 { 106 char **argv = toys.optargs; //file name. 107 toys.exitval = EXIT_SUCCESS; 108 109 if(!*argv) TT.do_cut(0); //for stdin 110 else { 111 for(; *argv; ++argv) { 112 if(strcmp(*argv, "-") == 0) TT.do_cut(0); //for stdin 113 else { 114 int fd = open(*argv, O_RDONLY, 0); 115 if (fd < 0) {//if file not present then continue with other files. 116 perror_msg_raw(*argv); 117 continue; 118 } 119 TT.do_cut(fd); 120 xclose(fd); 121 } 122 } 123 } 124 } 125 126 // perform cut operation on the given delimiter. 127 static void do_fcut(int fd) 128 { 129 char *buff, *pfield = 0, *delimiter = TT.delim; 130 131 for (;;) { 132 unsigned cpos = 0; 133 int start, ndelimiters = -1; 134 int nprinted_fields = 0; 135 struct slist *temp_node = TT.slist_head; 136 137 free(pfield); 138 pfield = 0; 139 140 if (!(buff = get_line(fd))) break; 141 142 //does line have any delimiter?. 143 if (strrchr(buff, (int)delimiter[0]) == NULL) { 144 //if not then print whole line and move to next line. 145 if (!(toys.optflags & FLAG_s)) xputs(buff); 146 continue; 147 } 148 149 pfield = xzalloc(strlen(buff) + 1); 150 151 if (temp_node) { 152 //process list on each line. 153 while (cpos < TT.nelem && buff) { 154 if (!temp_node) break; 155 start = temp_node->start; 156 do { 157 char *field = 0; 158 159 //count number of delimeters per line. 160 while (buff) { 161 if (ndelimiters < start) { 162 ndelimiters++; 163 field = strsep(&buff, delimiter); 164 } else break; 165 } 166 //print field (if not yet printed). 167 if (!pfield[ndelimiters]) { 168 if (ndelimiters == start) { 169 //put delimiter. 170 if (nprinted_fields++ > 0) xputc(delimiter[0]); 171 if (field) fputs(field, stdout); 172 //make sure this field won't print again. 173 pfield[ndelimiters] = (char) 0x23; //put some char at this position. 174 } 175 } 176 start++; 177 if ((temp_node->end < 0) || !buff) break; 178 } while(start <= temp_node->end); 179 temp_node = temp_node->next; 180 cpos++; 181 } 182 } 183 xputc('\n'); 184 } 185 } 186 187 // perform cut operation char or byte. 188 static void do_bccut(int fd) 189 { 190 char *buff; 191 192 while ((buff = get_line(fd)) != NULL) { 193 unsigned cpos = 0; 194 int buffln = strlen(buff); 195 char *pfield = xzalloc(buffln + 1); 196 struct slist *temp_node = TT.slist_head; 197 198 if (temp_node != NULL) { 199 while (cpos < TT.nelem) { 200 int start; 201 202 if (!temp_node) break; 203 start = temp_node->start; 204 while (start < buffln) { 205 //to avoid duplicate field printing. 206 if (pfield[start]) { 207 if (++start <= temp_node->end) continue; 208 temp_node = temp_node->next; 209 break; 210 } else { 211 //make sure this field won't print again. 212 pfield[start] = (char) 0x23; //put some char at this position. 213 xputc(buff[start]); 214 } 215 if (++start > temp_node->end) { 216 temp_node = temp_node->next; 217 break; 218 } 219 } 220 cpos++; 221 } 222 xputc('\n'); 223 } 224 free(pfield); 225 pfield = NULL; 226 } 227 } 228 229 void cut_main(void) 230 { 231 char delimiter = '\t'; //default delimiter. 232 char *list; 233 234 TT.nelem = 0; 235 TT.slist_head = NULL; 236 237 //Get list and assign the function. 238 if (toys.optflags & FLAG_f) { 239 list = TT.flist; 240 TT.do_cut = do_fcut; 241 } else if (toys.optflags & FLAG_c) { 242 list = TT.clist; 243 TT.do_cut = do_bccut; 244 } else { 245 list = TT.blist; 246 TT.do_cut = do_bccut; 247 } 248 249 if (toys.optflags & FLAG_d) { 250 //delimiter must be 1 char. 251 if(TT.delim[0] && TT.delim[1]) 252 perror_exit("the delimiter must be a single character"); 253 delimiter = TT.delim[0]; 254 } 255 256 if(!(toys.optflags & FLAG_d) && (toys.optflags & FLAG_f)) { 257 TT.delim = xzalloc(2); 258 TT.delim[0] = delimiter; 259 } 260 261 //when field is not specified, cutting has some special handling. 262 if (!(toys.optflags & FLAG_f)) { 263 if (toys.optflags & FLAG_s) 264 perror_exit("suppressing non-delimited lines operating on fields"); 265 if (delimiter != '\t') 266 perror_exit("an input delimiter may be specified only when operating on fields"); 267 } 268 269 parse_list(list); 270 get_data(); 271 if (!(toys.optflags & FLAG_d) && (toys.optflags & FLAG_f)) { 272 free(TT.delim); 273 TT.delim = NULL; 274 } 275 llist_traverse(TT.slist_head, free); 276 } 277