/* vi: set sw=4 ts=4: */ /* * cut.c - minimalist version of cut * * Copyright (C) 1999,2000,2001 by Lineo, inc. * Written by Mark Whitley <markw@codepoet.org> * debloated by Bernhard Reutner-Fischer * * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */ #include "libbb.h" /* This is a NOEXEC applet. Be very careful! */ /* option vars */ static const char optstring[] ALIGN1 = "b:c:f:d:sn"; #define CUT_OPT_BYTE_FLGS (1 << 0) #define CUT_OPT_CHAR_FLGS (1 << 1) #define CUT_OPT_FIELDS_FLGS (1 << 2) #define CUT_OPT_DELIM_FLGS (1 << 3) #define CUT_OPT_SUPPRESS_FLGS (1 << 4) struct cut_list { int startpos; int endpos; }; enum { BOL = 0, EOL = INT_MAX, NON_RANGE = -1 }; static int cmpfunc(const void *a, const void *b) { return (((struct cut_list *) a)->startpos - ((struct cut_list *) b)->startpos); } static void cut_file(FILE *file, char delim, const struct cut_list *cut_lists, unsigned nlists) { char *line; unsigned linenum = 0; /* keep these zero-based to be consistent */ /* go through every line in the file */ while ((line = xmalloc_fgetline(file)) != NULL) { /* set up a list so we can keep track of what's been printed */ int linelen = strlen(line); char *printed = xzalloc(linelen + 1); char *orig_line = line; unsigned cl_pos = 0; int spos; /* cut based on chars/bytes XXX: only works when sizeof(char) == byte */ if (option_mask32 & (CUT_OPT_CHAR_FLGS | CUT_OPT_BYTE_FLGS)) { /* print the chars specified in each cut list */ for (; cl_pos < nlists; cl_pos++) { spos = cut_lists[cl_pos].startpos; while (spos < linelen) { if (!printed[spos]) { printed[spos] = 'X'; putchar(line[spos]); } spos++; if (spos > cut_lists[cl_pos].endpos /* NON_RANGE is -1, so if below is true, * the above was true too (spos is >= 0) */ /* || cut_lists[cl_pos].endpos == NON_RANGE */ ) { break; } } } } else if (delim == '\n') { /* cut by lines */ spos = cut_lists[cl_pos].startpos; /* get out if we have no more lists to process or if the lines * are lower than what we're interested in */ if (((int)linenum < spos) || (cl_pos >= nlists)) goto next_line; /* if the line we're looking for is lower than the one we were * passed, it means we displayed it already, so move on */ while (spos < (int)linenum) { spos++; /* go to the next list if we're at the end of this one */ if (spos > cut_lists[cl_pos].endpos || cut_lists[cl_pos].endpos == NON_RANGE ) { cl_pos++; /* get out if there's no more lists to process */ if (cl_pos >= nlists) goto next_line; spos = cut_lists[cl_pos].startpos; /* get out if the current line is lower than the one * we just became interested in */ if ((int)linenum < spos) goto next_line; } } /* If we made it here, it means we've found the line we're * looking for, so print it */ puts(line); goto next_line; } else { /* cut by fields */ int ndelim = -1; /* zero-based / one-based problem */ int nfields_printed = 0; char *field = NULL; const char delimiter[2] = { delim, 0 }; /* does this line contain any delimiters? */ if (strchr(line, delim) == NULL) { if (!(option_mask32 & CUT_OPT_SUPPRESS_FLGS)) puts(line); goto next_line; } /* process each list on this line, for as long as we've got * a line to process */ for (; cl_pos < nlists && line; cl_pos++) { spos = cut_lists[cl_pos].startpos; do { /* find the field we're looking for */ while (line && ndelim < spos) { field = strsep(&line, delimiter); ndelim++; } /* we found it, and it hasn't been printed yet */ if (field && ndelim == spos && !printed[ndelim]) { /* if this isn't our first time through, we need to * print the delimiter after the last field that was * printed */ if (nfields_printed > 0) putchar(delim); fputs(field, stdout); printed[ndelim] = 'X'; nfields_printed++; /* shouldn't overflow.. */ } spos++; /* keep going as long as we have a line to work with, * this is a list, and we're not at the end of that * list */ } while (spos <= cut_lists[cl_pos].endpos && line && cut_lists[cl_pos].endpos != NON_RANGE); } } /* if we printed anything at all, we need to finish it with a * newline cuz we were handed a chomped line */ putchar('\n'); next_line: linenum++; free(printed); free(orig_line); } } int cut_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int cut_main(int argc UNUSED_PARAM, char **argv) { /* growable array holding a series of lists */ struct cut_list *cut_lists = NULL; unsigned nlists = 0; /* number of elements in above list */ char delim = '\t'; /* delimiter, default is tab */ char *sopt, *ltok; unsigned opt; opt_complementary = "b--bcf:c--bcf:f--bcf"; opt = getopt32(argv, optstring, &sopt, &sopt, &sopt, <ok); // argc -= optind; argv += optind; if (!(opt & (CUT_OPT_BYTE_FLGS | CUT_OPT_CHAR_FLGS | CUT_OPT_FIELDS_FLGS))) bb_error_msg_and_die("expected a list of bytes, characters, or fields"); if (opt & CUT_OPT_DELIM_FLGS) { if (ltok[0] && ltok[1]) { /* more than 1 char? */ bb_error_msg_and_die("the delimiter must be a single character"); } delim = ltok[0]; } /* non-field (char or byte) cutting has some special handling */ if (!(opt & CUT_OPT_FIELDS_FLGS)) { static const char _op_on_field[] ALIGN1 = " only when operating on fields"; if (opt & CUT_OPT_SUPPRESS_FLGS) { bb_error_msg_and_die ("suppressing non-delimited lines makes sense%s", _op_on_field); } if (delim != '\t') { bb_error_msg_and_die ("a delimiter may be specified%s", _op_on_field); } } /* * parse list and put values into startpos and endpos. * valid list formats: N, N-, N-M, -M * more than one list can be separated by commas */ { char *ntok; int s = 0, e = 0; /* take apart the lists, one by one (they are separated with commas) */ while ((ltok = strsep(&sopt, ",")) != NULL) { /* it's actually legal to pass an empty list */ if (!ltok[0]) continue; /* get the start pos */ ntok = strsep(<ok, "-"); if (!ntok[0]) { s = BOL; } else { s = xatoi_u(ntok); /* account for the fact that arrays are zero based, while * the user expects the first char on the line to be char #1 */ if (s != 0) s--; } /* get the end pos */ if (ltok == NULL) { e = NON_RANGE; } else if (!ltok[0]) { e = EOL; } else { e = xatoi_u(ltok); /* if the user specified and end position of 0, * that means "til the end of the line" */ if (e == 0) e = EOL; e--; /* again, arrays are zero based, lines are 1 based */ if (e == s) e = NON_RANGE; } /* add the new list */ cut_lists = xrealloc_vector(cut_lists, 4, nlists); /* NB: startpos is always >= 0, * while endpos may be = NON_RANGE (-1) */ cut_lists[nlists].startpos = s; cut_lists[nlists].endpos = e; nlists++; } /* make sure we got some cut positions out of all that */ if (nlists == 0) bb_error_msg_and_die("missing list of positions"); /* now that the lists are parsed, we need to sort them to make life * easier on us when it comes time to print the chars / fields / lines */ qsort(cut_lists, nlists, sizeof(struct cut_list), cmpfunc); } { int retval = EXIT_SUCCESS; if (!*argv) *--argv = (char *)"-"; do { FILE *file = fopen_or_warn_stdin(*argv); if (!file) { retval = EXIT_FAILURE; continue; } cut_file(file, delim, cut_lists, nlists); fclose_if_not_stdin(file); } while (*++argv); if (ENABLE_FEATURE_CLEAN_UP) free(cut_lists); fflush_stdout_and_exit(retval); } }