/* $OpenBSD: fmt.c,v 1.39 2018/10/18 05:04:52 otto Exp $ */ /* * This file is a derived work. * The changes are covered by the following Copyright and license: * * Copyright (c) 2015, 2016 Ingo Schwarze <schwarze@openbsd.org> * Copyright (c) 2000 Paul Janzen <pjanzen@foatdi.net> * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * * * The unchanged parts are covered by the following Copyright and license: * * Copyright (c) 1997 Gareth McCaughan. All rights reserved. * * Redistribution and use of this code, in source or binary forms, * with or without modification, are permitted subject to the following * conditions: * * - Redistribution of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - If you distribute modified source code it must also include * a notice saying that it has been modified, and giving a brief * description of what changes have been made. * * Disclaimer: I am not responsible for the results of using this code. * If it formats your hard disc, sends obscene messages to * your boss and kills your children then that's your problem * not mine. I give absolutely no warranty of any sort as to * what the program will do, and absolutely refuse to be held * liable for any consequences of your using it. * Thank you. Have a nice day. * * * Brief overview of the changes made by OpenBSD: * Added UTF-8 support (2016). * Added pledge(2) support (2015). * ANSI function syntax and KNF (2004). * Added -w option (2000). * Some minor changes can be seen in the public OpenBSD CVS repository. */ /* Sensible version of fmt * * Syntax: fmt [ options ] [ goal [ max ] ] [ filename ... ] * * Since the documentation for the original fmt is so poor, here * is an accurate description of what this one does. It's usually * the same. The *mechanism* used may differ from that suggested * here. Note that we are *not* entirely compatible with fmt, * because fmt gets so many things wrong. * * 1. Tabs are expanded, assuming 8-space tab stops. * If the `-t <n>' option is given, we assume <n>-space * tab stops instead. * Trailing blanks are removed from all lines. * x\b == nothing, for any x other than \b. * Other control characters are simply stripped. This * includes \r. * 2. Each line is split into leading whitespace and * everything else. Maximal consecutive sequences of * lines with the same leading whitespace are considered * to form paragraphs, except that a blank line is always * a paragraph to itself. * If the `-p' option is given then the first line of a * paragraph is permitted to have indentation different * from that of the other lines. * If the `-m' option is given then a line that looks * like a mail message header, if it is not immediately * preceded by a non-blank non-message-header line, is * taken to start a new paragraph, which also contains * any subsequent lines with non-empty leading whitespace. * Unless the `-n' option is given, lines beginning with * a . (dot) are not formatted. * 3. The "everything else" is split into words; a word * includes its trailing whitespace, and a word at the * end of a line is deemed to be followed by a single * space, or two spaces if it ends with a sentence-end * character. (See the `-d' option for how to change that.) * If the `-s' option has been given, then a word's trailing * whitespace is replaced by what it would have had if it * had occurred at end of line. * 4. Each paragraph is sent to standard output as follows. * We output the leading whitespace, and then enough words * to make the line length as near as possible to the goal * without exceeding the maximum. (If a single word would * exceed the maximum, we output that anyway.) Of course * the trailing whitespace of the last word is ignored. * We then emit a newline and start again if there are any * words left. * Note that for a blank line this translates as "We emit * a newline". * If the `-l <n>' option is given, then leading whitespace * is modified slightly: <n> spaces are replaced by a tab. * Indented paragraphs (see above under `-p') make matters * more complicated than this suggests. Actually every paragraph * has two `leading whitespace' values; the value for the first * line, and the value for the most recent line. (While processing * the first line, the two are equal. When `-p' has not been * given, they are always equal.) The leading whitespace * actually output is that of the first line (for the first * line of *output*) or that of the most recent line (for * all other lines of output). * When `-m' has been given, message header paragraphs are * taken as having first-leading-whitespace empty and * subsequent-leading-whitespace two spaces. * * Multiple input files are formatted one at a time, so that a file * never ends in the middle of a line. * * There's an alternative mode of operation, invoked by giving * the `-c' option. In that case we just center every line, * and most of the other options are ignored. This should * really be in a separate program, but we must stay compatible * with old `fmt'. * * QUERY: Should `-m' also try to do the right thing with quoted text? * QUERY: `-b' to treat backslashed whitespace as old `fmt' does? * QUERY: Option meaning `never join lines'? * QUERY: Option meaning `split in mid-word to avoid overlong lines'? * (Those last two might not be useful, since we have `fold'.) * * Differences from old `fmt': * * - We have many more options. Options that aren't understood * generate a lengthy usage message, rather than being * treated as filenames. * - Even with `-m', our handling of message headers is * significantly different. (And much better.) * - We don't treat `\ ' as non-word-breaking. * - Downward changes of indentation start new paragraphs * for us, as well as upward. (I think old `fmt' behaves * in the way it does in order to allow indented paragraphs, * but this is a broken way of making indented paragraphs * behave right.) * - Given the choice of going over or under |goal_length| * by the same amount, we go over; old `fmt' goes under. * - We treat `?' as ending a sentence, and not `:'. Old `fmt' * does the reverse. * - We return approved return codes. Old `fmt' returns * 1 for some errors, and *the number of unopenable files* * when that was all that went wrong. * - We have fewer crashes and more helpful error messages. * - We don't turn spaces into tabs at starts of lines unless * specifically requested. * - New `fmt' is somewhat smaller and slightly faster than * old `fmt'. * * Bugs: * * None known. There probably are some, though. * * Portability: * * I believe this code to be pretty portable. It does require * that you have `getopt'. If you need to include "getopt.h" * for this (e.g., if your system didn't come with `getopt' * and you installed it yourself) then you should arrange for * NEED_getopt_h to be #defined. * * Everything here should work OK even on nasty 16-bit * machines and nice 64-bit ones. However, it's only really * been tested on my FreeBSD machine. Your mileage may vary. */ #include <ctype.h> #include <err.h> #include <locale.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <wchar.h> #include <wctype.h> /* Something that, we hope, will never be a genuine line length, * indentation etc. */ #define SILLY ((size_t)-1) /* I used to use |strtoul| for this, but (1) not all systems have it * and (2) it's probably better to use |strtol| to detect negative * numbers better. * If |fussyp==0| then we don't complain about non-numbers * (returning 0 instead), but we do complain about bad numbers. */ static size_t get_positive(const char *s, const char *err_mess, int fussyP) { char *t; long result = strtol(s, &t, 0); if (*t) { if (fussyP) goto Lose; else return 0; } if (result <= 0) { Lose: errx(1, "%s", err_mess); } return (size_t) result; } /* Global variables */ static int centerP = 0; /* Try to center lines? */ static size_t goal_length = 0; /* Target length for output lines */ static size_t max_length = 0; /* Maximum length for output lines */ static int coalesce_spaces_P = 0; /* Coalesce multiple whitespace -> ' ' ? */ static int allow_indented_paragraphs = 0; /* Can first line have diff. ind.? */ static int tab_width = 8; /* Number of spaces per tab stop */ static size_t output_tab_width = 0; /* Ditto, when squashing leading spaces */ static const char *sentence_enders = ".?!"; /* Double-space after these */ static int grok_mail_headers = 0; /* treat embedded mail headers magically? */ static int format_troff = 0; /* Format troff? */ static int n_errors = 0; /* Number of failed files. */ static size_t x; /* Horizontal position in output line */ static size_t x0; /* Ditto, ignoring leading whitespace */ static size_t pending_spaces; /* Spaces to add before next word */ static int output_in_paragraph = 0; /* Any of current para written out yet? */ /* Prototypes */ static void process_named_file(const char *); static void process_stream(FILE *, const char *); static size_t indent_length(const char *); static int might_be_header(const char *); static void new_paragraph(size_t); static void output_word(size_t, size_t, const char *, int, int, int); static void output_indent(size_t); static void center_stream(FILE *, const char *); static char *get_line(FILE *); static void *xreallocarray(void *, size_t, size_t); void usage(void); #define ERRS(x) (x >= 127 ? 127 : ++x) /* Here is perhaps the right place to mention that this code is * all in top-down order. Hence, |main| comes first. */ int main(int argc, char *argv[]) { int ch; /* used for |getopt| processing */ (void)setlocale(LC_CTYPE, ""); if (pledge("stdio rpath", NULL) == -1) err(1, "pledge"); /* 1. Grok parameters. */ while ((ch = getopt(argc, argv, "0123456789cd:hl:mnpst:w:")) != -1) { switch (ch) { case 'c': centerP = 1; break; case 'd': sentence_enders = optarg; break; case 'l': output_tab_width = get_positive(optarg, "output tab width must be positive", 1); break; case 'm': grok_mail_headers = 1; break; case 'n': format_troff = 1; break; case 'p': allow_indented_paragraphs = 1; break; case 's': coalesce_spaces_P = 1; break; case 't': tab_width = get_positive(optarg, "tab width must be positive", 1); break; case 'w': goal_length = get_positive(optarg, "width must be positive", 1); max_length = goal_length; break; case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': /* XXX this is not a stylistically approved use of getopt() */ if (goal_length == 0) { char *p; p = argv[optind - 1]; if (p[0] == '-' && p[1] == ch && !p[2]) goal_length = get_positive(++p, "width must be nonzero", 1); else goal_length = get_positive(argv[optind]+1, "width must be nonzero", 1); max_length = goal_length; } break; case 'h': default: usage(); /* NOT REACHED */ } } argc -= optind; argv += optind; /* [ goal [ maximum ] ] */ if (argc > 0 && goal_length == 0 && (goal_length = get_positive(*argv,"goal length must be positive", 0)) != 0) { --argc; ++argv; if (argc > 0 && (max_length = get_positive(*argv,"max length must be positive", 0)) != 0) { --argc; ++argv; if (max_length < goal_length) errx(1, "max length must be >= goal length"); } } if (goal_length == 0) goal_length = 65; if (max_length == 0) max_length = goal_length+10; /* 2. Process files. */ if (argc > 0) { while (argc-- > 0) process_named_file(*argv++); } else { if (pledge("stdio", NULL) == -1) err(1, "pledge"); process_stream(stdin, "standard input"); } /* We're done. */ return n_errors; } /* Process a single file, given its name. */ static void process_named_file(const char *name) { FILE *f; if ((f = fopen(name, "r")) == NULL) { warn("%s", name); ERRS(n_errors); } else { process_stream(f, name); fclose(f); } } /* Types of mail header continuation lines: */ typedef enum { hdr_ParagraphStart = -1, hdr_NonHeader = 0, hdr_Header = 1, hdr_Continuation = 2 } HdrType; /* Process a stream. This is where the real work happens, * except that centering is handled separately. */ static void process_stream(FILE *stream, const char *name) { const char *wordp, *cp; wchar_t wc; size_t np; size_t last_indent = SILLY; /* how many spaces in last indent? */ size_t para_line_number = 0; /* how many lines already read in this para? */ size_t first_indent = SILLY; /* indentation of line 0 of paragraph */ int wcl; /* number of bytes in wide character */ int wcw; /* display width of wide character */ int word_length; /* number of bytes in word */ int word_width; /* display width of word */ int space_width; /* display width of space after word */ int line_width; /* display width of line */ HdrType prev_header_type = hdr_ParagraphStart; HdrType header_type; /* ^-- header_type of previous line; -1 at para start */ const char *line; if (centerP) { center_stream(stream, name); return; } while ((line = get_line(stream)) != NULL) { np = indent_length(line); header_type = hdr_NonHeader; if (grok_mail_headers && prev_header_type != hdr_NonHeader) { if (np == 0 && might_be_header(line)) header_type = hdr_Header; else if (np > 0 && prev_header_type>hdr_NonHeader) header_type = hdr_Continuation; } /* We need a new paragraph if and only if: * this line is blank, * OR it's a troff request, * OR it's a mail header, * OR it's not a mail header AND the last line was one, * OR the indentation has changed * AND the line isn't a mail header continuation line * AND this isn't the second line of an indented paragraph. */ if (*line == '\0' || (*line == '.' && !format_troff) || header_type == hdr_Header || (header_type == hdr_NonHeader && prev_header_type > hdr_NonHeader) || (np != last_indent && header_type != hdr_Continuation && (!allow_indented_paragraphs || para_line_number != 1)) ) { new_paragraph(np); para_line_number = 0; first_indent = np; last_indent = np; /* nroff compatibility */ if (*line == '.' && !format_troff) { puts(line); continue; } if (header_type == hdr_Header) last_indent = 2; /* for cont. lines */ if (*line == '\0') { putchar('\n'); prev_header_type = hdr_ParagraphStart; continue; } else { /* If this is an indented paragraph other than a mail header * continuation, set |last_indent|. */ if (np != last_indent && header_type != hdr_Continuation) last_indent = np; } prev_header_type = header_type; } line_width = np; for (wordp = line; *wordp != '\0'; wordp = cp) { word_length = 0; word_width = space_width = 0; for (cp = wordp; *cp != '\0'; cp += wcl) { wcl = mbtowc(&wc, cp, MB_CUR_MAX); if (wcl == -1) { (void)mbtowc(NULL, NULL, MB_CUR_MAX); wc = L'?'; wcl = 1; wcw = 1; } else if (wc == L'\t') wcw = (line_width / tab_width + 1) * tab_width - line_width; else if ((wcw = wcwidth(wc)) == -1) wcw = 1; if (iswblank(wc) && wc != 0xa0) { /* Skip whitespace at start of line. */ if (word_length == 0) { wordp += wcl; continue; } /* Count whitespace after word. */ space_width += wcw; } else { /* Detect end of word. */ if (space_width > 0) break; /* Measure word. */ word_length += wcl; word_width += wcw; } line_width += wcw; } /* Send the word to the output machinery. */ output_word(first_indent, last_indent, wordp, word_length, word_width, space_width); } ++para_line_number; } new_paragraph(0); if (ferror(stream)) { warn("%s", name); ERRS(n_errors); } } /* How long is the indent on this line? */ static size_t indent_length(const char *line) { size_t n = 0; for (;;) { switch(*line++) { case ' ': ++n; continue; case '\t': n = (n / tab_width + 1) * tab_width; continue; default: break; } break; } return n; } /* Might this line be a mail header? * We deem a line to be a possible header if it matches the * Perl regexp /^[A-Z][-A-Za-z0-9]*:\s/. This is *not* the same * as in RFC whatever-number-it-is; we want to be gratuitously * conservative to avoid mangling ordinary civilised text. */ static int might_be_header(const char *line) { if (!isupper((unsigned char)*line++)) return 0; while (isalnum((unsigned char)*line) || *line == '-') ++line; return (*line == ':' && isspace((unsigned char)line[1])); } /* Begin a new paragraph with an indent of |indent| spaces. */ static void new_paragraph(size_t indent) { if (x0 > 0) putchar('\n'); x = indent; x0 = 0; pending_spaces = 0; output_in_paragraph = 0; } /* Output spaces or tabs for leading indentation. */ static void output_indent(size_t n_spaces) { if (n_spaces == 0) return; if (output_tab_width) { while (n_spaces >= output_tab_width) { putchar('\t'); n_spaces -= output_tab_width; } } while (n_spaces-- > 0) putchar(' '); } /* Output a single word. * indent0 and indent1 are the indents to use on the first and subsequent * lines of a paragraph. They'll often be the same, of course. */ static void output_word(size_t indent0, size_t indent1, const char *word, int length, int width, int spaces) { size_t new_x = x + pending_spaces + width; /* If either |spaces==0| (at end of line) or |coalesce_spaces_P| * (squashing internal whitespace), then add just one space; * except that if the last character was a sentence-ender we * actually add two spaces. */ if (coalesce_spaces_P || spaces == 0) spaces = strchr(sentence_enders, word[length-1]) ? 2 : 1; if (x0 == 0) output_indent(output_in_paragraph ? indent1 : indent0); else if (new_x > max_length || x >= goal_length || (new_x > goal_length && new_x-goal_length > goal_length-x)) { putchar('\n'); output_indent(indent1); x0 = 0; x = indent1; } else { x0 += pending_spaces; x += pending_spaces; while (pending_spaces--) putchar(' '); } x0 += width; x += width; while(length--) putchar(*word++); pending_spaces = spaces; output_in_paragraph = 1; } /* Process a stream, but just center its lines rather than trying to * format them neatly. */ static void center_stream(FILE *stream, const char *name) { char *line, *cp; wchar_t wc; size_t l; /* Display width of the line. */ int wcw; /* Display width of one character. */ int wcl; /* Length in bytes of one character. */ while ((line = get_line(stream)) != NULL) { l = 0; for (cp = line; *cp != '\0'; cp += wcl) { if (*cp == '\t') *cp = ' '; if ((wcl = mbtowc(&wc, cp, MB_CUR_MAX)) == -1) { (void)mbtowc(NULL, NULL, MB_CUR_MAX); *cp = '?'; wcl = 1; wcw = 1; } else if ((wcw = wcwidth(wc)) == -1) wcw = 1; if (l == 0 && iswspace(wc)) line += wcl; else l += wcw; } while (l < goal_length) { putchar(' '); l += 2; } puts(line); } if (ferror(stream)) { warn("%s", name); ERRS(n_errors); } } /* Get a single line from a stream. Strip control * characters and trailing whitespace, and handle backspaces. * Return the address of the buffer containing the line. * This can cope with arbitrarily long lines, and with lines * without terminating \n. * If there are no characters left or an error happens, we * return NULL. */ static char * get_line(FILE *stream) { int ch; int troff = 0; static char *buf = NULL; static size_t length = 0; size_t len = 0; if (buf == NULL) { length = 100; buf = xreallocarray(NULL, length, 1); } while ((ch = getc(stream)) != '\n' && ch != EOF) { if ((len == 0) && (ch == '.' && !format_troff)) troff = 1; if (troff || ch == '\t' || !iscntrl(ch)) { if (len >= length - 1) { buf = xreallocarray(buf, length, 2); length *= 2; } buf[len++] = ch; } else if (ch == '\b') { if (len) --len; } } while (len > 0 && isspace((unsigned char)buf[len-1])) --len; buf[len] = '\0'; return (len > 0 || ch != EOF) ? buf : NULL; } /* (Re)allocate some memory, exiting with an error if we can't. */ static void * xreallocarray(void *ptr, size_t nmemb, size_t size) { void *p; p = reallocarray(ptr, nmemb, size); if (p == NULL) errx(1, "out of memory"); return p; } void usage(void) { extern char *__progname; fprintf(stderr, "usage: %s [-cmnps] [-d chars] [-l number] [-t number]\n" "\t[goal [maximum] | -width | -w width] [file ...]\n", __progname); exit (1); }
