/* cut.c - Cut from a file.
*
* Copyright 2012 Ranjan Kumar <ranjankumar.bth@gmail.com>
* Copyright 2012 Kyungwan Han <asura321@gmail.com>
*
* http://pubs.opengroup.org/onlinepubs/9699919799/utilities/cut.html
*
* TODO: cleanup
USE_CUT(NEWTOY(cut, "b:|c:|f:|d:sn[!cbf]", TOYFLAG_USR|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"
GLOBALS(
char *delim;
char *flist;
char *clist;
char *blist;
void *slist_head;
unsigned nelem;
void (*do_cut)(int fd);
)
struct slist {
struct slist *next;
int start, end;
};
static void add_to_list(int start, int end)
{
struct slist *current, *head_ref, *temp1_node;
head_ref = TT.slist_head;
temp1_node = xzalloc(sizeof(struct slist));
temp1_node->start = start;
temp1_node->end = end;
/* Special case for the head end */
if (!head_ref || head_ref->start >= 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 && current->next->start < temp1_node->start)
current = current->next;
temp1_node->next = current->next;
current->next = temp1_node;
}
TT.slist_head = head_ref;
}
// parse list and add to slist.
static void parse_list(char *list)
{
for (;;) {
char *ctoken = strsep(&list, ","), *dtoken;
int start = 0, end = INT_MAX;
if (!ctoken) break;
if (!*ctoken) continue;
//Get start position.
if (*(dtoken = strsep(&ctoken, "-"))) {
start = atolx_range(dtoken, 0, INT_MAX);
start = (start?(start-1):start);
}
//Get end position.
if (!ctoken) end = -1; //case e.g. 1,2,3
else if (*ctoken) {//case e.g. N-M
end = atolx_range(ctoken, 0, INT_MAX);
if (!end) end = INT_MAX;
end--;
if(end == start) end = -1;
}
add_to_list(start, end);
TT.nelem++;
}
//if list is missing in command line.
if (!TT.nelem) error_exit("missing positions list");
}
/*
* retrive data from the file/s.
*/
static void get_data(void)
{
char **argv = toys.optargs; //file name.
toys.exitval = EXIT_SUCCESS;
if(!*argv) TT.do_cut(0); //for stdin
else {
for(; *argv; ++argv) {
if(strcmp(*argv, "-") == 0) TT.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_raw(*argv);
continue;
}
TT.do_cut(fd);
xclose(fd);
}
}
}
}
// perform cut operation on the given delimiter.
static void do_fcut(int fd)
{
char *buff, *pfield = 0, *delimiter = TT.delim;
for (;;) {
unsigned cpos = 0;
int start, ndelimiters = -1;
int nprinted_fields = 0;
struct slist *temp_node = TT.slist_head;
free(pfield);
pfield = 0;
if (!(buff = get_line(fd))) break;
//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;
}
pfield = xzalloc(strlen(buff) + 1);
if (temp_node) {
//process list on each line.
while (cpos < TT.nelem && buff) {
if (!temp_node) break;
start = temp_node->start;
do {
char *field = 0;
//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 < 0) || !buff) break;
} while(start <= temp_node->end);
temp_node = temp_node->next;
cpos++;
}
}
xputc('\n');
}
}
// 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);
struct slist *temp_node = TT.slist_head;
if (temp_node != NULL) {
while (cpos < TT.nelem) {
int start;
if (!temp_node) break;
start = temp_node->start;
while (start < buffln) {
//to avoid duplicate field printing.
if (pfield[start]) {
if (++start <= temp_node->end) 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) {
temp_node = temp_node->next;
break;
}
}
cpos++;
}
xputc('\n');
}
free(pfield);
pfield = NULL;
}
}
void cut_main(void)
{
char delimiter = '\t'; //default delimiter.
char *list;
TT.nelem = 0;
TT.slist_head = NULL;
//Get list and assign the function.
if (toys.optflags & FLAG_f) {
list = TT.flist;
TT.do_cut = do_fcut;
} else if (toys.optflags & FLAG_c) {
list = TT.clist;
TT.do_cut = do_bccut;
} else {
list = TT.blist;
TT.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 = 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;
}
llist_traverse(TT.slist_head, free);
}