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-rw-r--r--toys/posix/cut.c328
1 files changed, 328 insertions, 0 deletions
diff --git a/toys/posix/cut.c b/toys/posix/cut.c
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+/* cut.c - Cut from a file.
+ *
+ * Copyright 2012 Ranjan Kumar <ranjankumar.bth@gmail.com>, Kyungwan Han <asura321@gamil.com>
+ *
+ * http://pubs.opengroup.org/onlinepubs/9699919799/utilities/cut.html
+ *
+USE_CUT(NEWTOY(cut, "b:c:f:d:sn", TOYFLAG_BIN))
+
+config CUT
+ bool "cut"
+ default y
+ help
+ usage: cut OPTION... [FILE]...
+ Print selected parts of lines from each FILE to standard output.
+ -b LIST select only these bytes from LIST.
+ -c LIST select only these characters from LIST.
+ -f LIST select only these fields.
+ -d DELIM use DELIM instead of TAB for field delimiter.
+ -s do not print lines not containing delimiters.
+ -n don't split multibyte characters (Ignored).
+*/
+#define FOR_cut
+#include "toys.h"
+
+typedef struct _slist {
+ int start_position;
+ int end_position;
+ struct _slist *next;
+}SLIST;
+
+GLOBALS(
+ char *delim;
+ char *flist;
+ char *clist;
+ char *blist;
+ struct _slist *slist_head;
+ unsigned nelem;
+)
+
+#define BEGINOFLINE 0
+#define ENDOFLINE INT_MAX
+#define NORANGE -1
+
+static int get_user_options(void);
+void (*do_cut)(int);
+static void do_fcut(int fd);
+static void do_bccut(int fd);
+static void free_list(void);
+
+/*
+ * add items in the slist.
+ */
+static void add_to_list(int start, int end)
+{
+ SLIST *current, *head_ref, *temp1_node;
+
+ head_ref = TT.slist_head;
+ temp1_node = (SLIST *)xzalloc(sizeof(SLIST));
+ temp1_node->start_position = start;
+ temp1_node->end_position = end;
+ temp1_node->next = NULL;
+
+ /* Special case for the head end */
+ if (head_ref == NULL || (head_ref)->start_position >= start) {
+ temp1_node->next = head_ref;
+ head_ref = temp1_node;
+ }
+ else {
+ /* Locate the node before the point of insertion */
+ current = head_ref;
+ while (current->next!=NULL && current->next->start_position < temp1_node->start_position)
+ current = current->next;
+ temp1_node->next = current->next;
+ current->next = temp1_node;
+ }
+ TT.slist_head = head_ref;
+ return;
+}
+
+/*
+ * parse list and add to slist.
+ */
+static void parse_list(char *list)
+{
+ char *ctoken, *dtoken;
+ int start = 0, end = 0;
+ while((ctoken = strsep(&list, ",")) != NULL) {
+ if(!ctoken[0]) continue;
+
+ //Get start position.
+ dtoken = strsep(&ctoken, "-");
+ if(!dtoken[0]) start = BEGINOFLINE;
+ else {
+ start = get_int_value(dtoken, 0, INT_MAX);
+ start = (start?(start-1):start);
+ }
+ //Get end position.
+ if(ctoken == NULL) end = NORANGE; //case e.g. 1,2,3
+ else if(!ctoken[0]) end = ENDOFLINE; //case e.g. N-
+ else {//case e.g. N-M
+ end = get_int_value(ctoken, 0, INT_MAX);
+ end = (end?end:ENDOFLINE);
+ end--;
+ if(end == start) end = NORANGE;
+ }
+ add_to_list(start, end);
+ TT.nelem++;
+ }
+ //if list is missing in command line.
+ if(TT.nelem == 0) error_exit("missing positions list:");
+ return;
+}
+
+/*
+ * retrive data from the file/s.
+ */
+static void get_data(void)
+{
+ char **argv = toys.optargs; //file name.
+ toys.exitval = EXIT_SUCCESS;
+
+ if(!*argv) do_cut(0); //for stdin
+ else {
+ for(; *argv; ++argv) {
+ if(strcmp(*argv, "-") == 0) do_cut(0); //for stdin
+ else {
+ int fd = open(*argv, O_RDONLY, 0);
+ if(fd < 0) {//if file not present then continue with other files.
+ perror_msg(*argv);
+ toys.exitval = EXIT_FAILURE;
+ continue;
+ }
+ do_cut(fd);
+ xclose(fd);
+ }
+ }
+ }
+ return;
+}
+
+/*
+ * cut main function.
+*/
+void cut_main(void)
+{
+ char delimiter = '\t'; //default delimiter.
+ int num_of_options = 0;
+ char *list;
+
+ TT.nelem = 0;
+ TT.slist_head = NULL;
+ //verify the number of options provided by user.
+ num_of_options = get_user_options();
+ if(num_of_options == 0) error_exit("specify a list of bytes, characters, or fields");
+ else if(num_of_options > 1) error_exit("only one type of list may be specified");
+
+ //Get list and assign the function.
+ if(toys.optflags & FLAG_f) {
+ list = TT.flist;
+ do_cut = do_fcut;
+ }
+ else if(toys.optflags & FLAG_c) {
+ list = TT.clist;
+ do_cut = do_bccut;
+ }
+ else {
+ list = TT.blist;
+ do_cut = do_bccut;
+ }
+
+ if(toys.optflags & FLAG_d) {
+ //delimiter must be 1 char.
+ if(TT.delim[0] && TT.delim[1]) perror_exit("the delimiter must be a single character");
+ delimiter = TT.delim[0];
+ }
+
+ if(!(toys.optflags & FLAG_d) && (toys.optflags & FLAG_f)) {
+ TT.delim = (char *)xzalloc(2);
+ TT.delim[0] = delimiter;
+ }
+
+ //when field is not specified, cutting has some special handling.
+ if(!(toys.optflags & FLAG_f)) {
+ if(toys.optflags & FLAG_s) perror_exit("suppressing non-delimited lines operating on fields");
+ if(delimiter != '\t') perror_exit("an input delimiter may be specified only when operating on fields");
+ }
+
+ parse_list(list);
+ get_data();
+ if(!(toys.optflags & FLAG_d) && (toys.optflags & FLAG_f)) {
+ free(TT.delim);
+ TT.delim = NULL;
+ }
+ free_list();
+ return;
+}
+
+/*
+ * perform cut operation on the given delimiter.
+ */
+static void do_fcut(int fd)
+{
+ char *buff;
+ char *delimiter = TT.delim;
+ while((buff = get_line(fd)) != NULL) {
+ //does line have any delimiter?.
+ if(strrchr(buff, (int)delimiter[0]) == NULL) {
+ //if not then print whole line and move to next line.
+ if(!(toys.optflags & FLAG_s)) xputs(buff);
+ continue;
+ }
+
+ unsigned cpos = 0;
+ int start, ndelimiters = -1;
+ int nprinted_fields = 0;
+ char *pfield = xzalloc(strlen(buff) + 1);
+ SLIST *temp_node = TT.slist_head;
+
+ if(temp_node != NULL) {
+ //process list on each line.
+ while(cpos < TT.nelem && buff) {
+ if(!temp_node) break;
+ start = temp_node->start_position;
+ do {
+ char *field = NULL;
+ //count number of delimeters per line.
+ while(buff) {
+ if(ndelimiters < start) {
+ ndelimiters++;
+ field = strsep(&buff, delimiter);
+ }
+ else break;
+ }
+ //print field (if not yet printed).
+ if(!pfield[ndelimiters]) {
+ if(ndelimiters == start) {
+ //put delimiter.
+ if(nprinted_fields++ > 0) xputc(delimiter[0]);
+ if(field) fputs(field, stdout);
+ //make sure this field won't print again.
+ pfield[ndelimiters] = (char) 0x23; //put some char at this position.
+ }
+ }
+ start++;
+ if((temp_node->end_position == NORANGE) || (!buff)) break;
+ }while(start <= temp_node->end_position);
+ temp_node = temp_node->next;
+ cpos++;
+ }
+ }
+ xputc('\n');
+ free(pfield);
+ pfield = NULL;
+ }//End of while loop.
+ return;
+}
+
+/*
+ * perform cut operation char or byte.
+ */
+static void do_bccut(int fd)
+{
+ char *buff;
+ while((buff = get_line(fd)) != NULL) {
+ unsigned cpos = 0;
+ int buffln = strlen(buff);
+ char *pfield = xzalloc(buffln + 1);
+ SLIST *temp_node = TT.slist_head;
+ if(temp_node != NULL) {
+ while(cpos < TT.nelem) {
+ int start;
+ if(!temp_node) break;
+ start = temp_node->start_position;
+ while(start < buffln) {
+ //to avoid duplicate field printing.
+ if(pfield[start]) {
+ if(++start <= temp_node->end_position) continue;
+ temp_node = temp_node->next;
+ break;
+ }
+ else {
+ //make sure this field won't print again.
+ pfield[start] = (char) 0x23; //put some char at this position.
+ xputc(buff[start]);
+ }
+ if(++start > temp_node->end_position) {
+ temp_node = temp_node->next;
+ break;
+ }
+ }
+ cpos++;
+ }
+ xputc('\n');
+ }
+ free(pfield);
+ pfield = NULL;
+ }
+ return;
+}
+
+/*
+ * used to verify "c", "b" and "f" options are present in command line.
+ * As cut command can only except any of them at a time.
+*/
+static int get_user_options(void)
+{
+ int i = 3, flag = 0;
+ for(; i<6; i++) {//verify 3rd, 4th and 5th bit is set.
+ int mask = 1;
+ mask = mask << i;
+ if(toys.optflags & mask) flag++;
+ }
+ return flag;
+}
+
+/*
+ * free the slist.
+*/
+static void free_list(void)
+{
+ SLIST *temp;
+ while(TT.slist_head != NULL) {
+ temp = TT.slist_head->next;
+ free(TT.slist_head);
+ TT.slist_head = temp;
+ }
+ return;
+}