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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 17:39:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 17:39:29 +0000 |
commit | 8ffec2a3aba6f114784e11f89ef1d57a096ae540 (patch) | |
tree | ccebcbad06203e8241a8e7249f8e6c478a3682ea /src/unexpand.c | |
parent | Initial commit. (diff) | |
download | coreutils-8ffec2a3aba6f114784e11f89ef1d57a096ae540.tar.xz coreutils-8ffec2a3aba6f114784e11f89ef1d57a096ae540.zip |
Adding upstream version 8.32.upstream/8.32upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/unexpand.c')
-rw-r--r-- | src/unexpand.c | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/src/unexpand.c b/src/unexpand.c new file mode 100644 index 0000000..09dafdb --- /dev/null +++ b/src/unexpand.c @@ -0,0 +1,326 @@ +/* unexpand - convert blanks to tabs + Copyright (C) 1989-2020 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +/* By default, convert only maximal strings of initial blanks and tabs + into tabs. + Preserves backspace characters in the output; they decrement the + column count for tab calculations. + The default action is equivalent to -8. + + Options: + --tabs=tab1[,tab2[,...]] + -t tab1[,tab2[,...]] + -tab1[,tab2[,...]] If only one tab stop is given, set the tabs tab1 + columns apart instead of the default 8. Otherwise, + set the tabs at columns tab1, tab2, etc. (numbered from + 0); preserve any blanks beyond the tab stops given. + --all + -a Use tabs wherever they would replace 2 or more blanks, + not just at the beginnings of lines. + + David MacKenzie <djm@gnu.ai.mit.edu> */ + +#include <config.h> + +#include <stdio.h> +#include <getopt.h> +#include <sys/types.h> +#include "system.h" +#include "die.h" +#include "xstrndup.h" + +#include "expand-common.h" + +/* The official name of this program (e.g., no 'g' prefix). */ +#define PROGRAM_NAME "unexpand" + +#define AUTHORS proper_name ("David MacKenzie") + + + +/* For long options that have no equivalent short option, use a + non-character as a pseudo short option, starting with CHAR_MAX + 1. */ +enum +{ + CONVERT_FIRST_ONLY_OPTION = CHAR_MAX + 1 +}; + +static struct option const longopts[] = +{ + {"tabs", required_argument, NULL, 't'}, + {"all", no_argument, NULL, 'a'}, + {"first-only", no_argument, NULL, CONVERT_FIRST_ONLY_OPTION}, + {GETOPT_HELP_OPTION_DECL}, + {GETOPT_VERSION_OPTION_DECL}, + {NULL, 0, NULL, 0} +}; + +void +usage (int status) +{ + if (status != EXIT_SUCCESS) + emit_try_help (); + else + { + printf (_("\ +Usage: %s [OPTION]... [FILE]...\n\ +"), + program_name); + fputs (_("\ +Convert blanks in each FILE to tabs, writing to standard output.\n\ +"), stdout); + + emit_stdin_note (); + emit_mandatory_arg_note (); + + fputs (_("\ + -a, --all convert all blanks, instead of just initial blanks\n\ + --first-only convert only leading sequences of blanks (overrides -a)\n\ + -t, --tabs=N have tabs N characters apart instead of 8 (enables -a)\n\ +"), stdout); + emit_tab_list_info (); + fputs (HELP_OPTION_DESCRIPTION, stdout); + fputs (VERSION_OPTION_DESCRIPTION, stdout); + emit_ancillary_info (PROGRAM_NAME); + } + exit (status); +} + +/* Change blanks to tabs, writing to stdout. + Read each file in 'file_list', in order. */ + +static void +unexpand (void) +{ + /* Input stream. */ + FILE *fp = next_file (NULL); + + /* The array of pending blanks. In non-POSIX locales, blanks can + include characters other than spaces, so the blanks must be + stored, not merely counted. */ + char *pending_blank; + + if (!fp) + return; + + /* The worst case is a non-blank character, then one blank, then a + tab stop, then MAX_COLUMN_WIDTH - 1 blanks, then a non-blank; so + allocate MAX_COLUMN_WIDTH bytes to store the blanks. */ + pending_blank = xmalloc (max_column_width); + + while (true) + { + /* Input character, or EOF. */ + int c; + + /* If true, perform translations. */ + bool convert = true; + + + /* The following variables have valid values only when CONVERT + is true: */ + + /* Column of next input character. */ + uintmax_t column = 0; + + /* Column the next input tab stop is on. */ + uintmax_t next_tab_column = 0; + + /* Index in TAB_LIST of next tab stop to examine. */ + size_t tab_index = 0; + + /* If true, the first pending blank came just before a tab stop. */ + bool one_blank_before_tab_stop = false; + + /* If true, the previous input character was a blank. This is + initially true, since initial strings of blanks are treated + as if the line was preceded by a blank. */ + bool prev_blank = true; + + /* Number of pending columns of blanks. */ + size_t pending = 0; + + + /* Convert a line of text. */ + + do + { + while ((c = getc (fp)) < 0 && (fp = next_file (fp))) + continue; + + if (convert) + { + bool blank = !! isblank (c); + + if (blank) + { + bool last_tab IF_LINT (=0); + + next_tab_column = get_next_tab_column (column, &tab_index, + &last_tab); + + if (last_tab) + convert = false; + + if (convert) + { + if (next_tab_column < column) + die (EXIT_FAILURE, 0, _("input line is too long")); + + if (c == '\t') + { + column = next_tab_column; + + if (pending) + pending_blank[0] = '\t'; + } + else + { + column++; + + if (! (prev_blank && column == next_tab_column)) + { + /* It is not yet known whether the pending blanks + will be replaced by tabs. */ + if (column == next_tab_column) + one_blank_before_tab_stop = true; + pending_blank[pending++] = c; + prev_blank = true; + continue; + } + + /* Replace the pending blanks by a tab or two. */ + pending_blank[0] = c = '\t'; + } + + /* Discard pending blanks, unless it was a single + blank just before the previous tab stop. */ + pending = one_blank_before_tab_stop; + } + } + else if (c == '\b') + { + /* Go back one column, and force recalculation of the + next tab stop. */ + column -= !!column; + next_tab_column = column; + tab_index -= !!tab_index; + } + else + { + column++; + if (!column) + die (EXIT_FAILURE, 0, _("input line is too long")); + } + + if (pending) + { + if (pending > 1 && one_blank_before_tab_stop) + pending_blank[0] = '\t'; + if (fwrite (pending_blank, 1, pending, stdout) != pending) + die (EXIT_FAILURE, errno, _("write error")); + pending = 0; + one_blank_before_tab_stop = false; + } + + prev_blank = blank; + convert &= convert_entire_line || blank; + } + + if (c < 0) + { + free (pending_blank); + return; + } + + if (putchar (c) < 0) + die (EXIT_FAILURE, errno, _("write error")); + } + while (c != '\n'); + } +} + +int +main (int argc, char **argv) +{ + bool have_tabval = false; + uintmax_t tabval IF_LINT ( = 0); + int c; + + /* If true, cancel the effect of any -a (explicit or implicit in -t), + so that only leading blanks will be considered. */ + bool convert_first_only = false; + + initialize_main (&argc, &argv); + set_program_name (argv[0]); + setlocale (LC_ALL, ""); + bindtextdomain (PACKAGE, LOCALEDIR); + textdomain (PACKAGE); + + atexit (close_stdout); + + while ((c = getopt_long (argc, argv, ",0123456789at:", longopts, NULL)) + != -1) + { + switch (c) + { + case '?': + usage (EXIT_FAILURE); + case 'a': + convert_entire_line = true; + break; + case 't': + convert_entire_line = true; + parse_tab_stops (optarg); + break; + case CONVERT_FIRST_ONLY_OPTION: + convert_first_only = true; + break; + case ',': + if (have_tabval) + add_tab_stop (tabval); + have_tabval = false; + break; + case_GETOPT_HELP_CHAR; + case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS); + default: + if (!have_tabval) + { + tabval = 0; + have_tabval = true; + } + if (!DECIMAL_DIGIT_ACCUMULATE (tabval, c - '0', uintmax_t)) + die (EXIT_FAILURE, 0, _("tab stop value is too large")); + break; + } + } + + if (convert_first_only) + convert_entire_line = false; + + if (have_tabval) + add_tab_stop (tabval); + + finalize_tab_stops (); + + set_file_list ( (optind < argc) ? &argv[optind] : NULL); + + unexpand (); + + cleanup_file_list_stdin (); + + return exit_status; +} |