/* $OpenBSD: fmt.c,v 1.21 2004/04/01 23:14:19 tedu Exp $ */ /* 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. */ /* 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. */ /* RCS change log: * Revision 1.5 1998/03/02 18:02:21 gjm11 * Minor changes for portability. * * Revision 1.4 1997/10/01 11:51:28 gjm11 * Repair broken indented-paragraph handling. * Add mail message header stuff. * Improve comments and layout. * Make usable with non-BSD systems. * Add revision display to usage message. * * Revision 1.3 1997/09/30 16:24:47 gjm11 * Add copyright notice, rcsid string and log message. * * Revision 1.2 1997/09/30 16:13:39 gjm11 * Add options: -d <chars>, -l <width>, -p, -s, -t <width>, -h . * Parse options with `getopt'. Clean up code generally. * Make comments more accurate. * * Revision 1.1 1997/09/30 11:29:57 gjm11 * Initial revision */ #ifndef lint static const char copyright[] = "Copyright (c) 1997 Gareth McCaughan. All rights reserved.\n"; #endif /* not lint */ #include <sys/cdefs.h> #include <err.h> #include <limits.h> #include <locale.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sysexits.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(EX_USAGE, "%s", err_mess); } return (size_t)result; } static size_t get_nonnegative(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(EX_USAGE, "%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 = 8; /* Ditto, when squashing leading spaces */ static const wchar_t *sentence_enders = L".?!"; /* 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. Return on exit. */ static wchar_t *output_buffer = NULL; /* Output line will be built here */ static size_t x; /* Horizontal position in output line */ static size_t x0; /* Ditto, ignoring leading whitespace */ static size_t output_buffer_length = 0; 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 wchar_t *, size_t); static int might_be_header(const wchar_t *); static void new_paragraph(size_t, size_t); static void output_word(size_t, size_t, const wchar_t *, size_t, size_t); static void output_indent(size_t); static void center_stream(FILE *, const char *); static wchar_t *get_line(FILE *, size_t *); static void *xrealloc(void *, size_t); #define XMALLOC(x) xrealloc(0,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 */ wchar_t *tmp; size_t len; const char *src; (void)setlocale(LC_CTYPE, ""); /* 1. Grok parameters. */ while ((ch = getopt(argc, argv, "0123456789cd:hl:mnpst:w:")) != -1) switch (ch) { case 'c': centerP = 1; format_troff = 1; continue; case 'd': src = optarg; len = mbsrtowcs(NULL, &src, 0, NULL); if (len == (size_t)-1) err(EX_USAGE, "bad sentence-ending character set"); tmp = XMALLOC((len + 1) * sizeof(wchar_t)); mbsrtowcs(tmp, &src, len + 1, NULL); sentence_enders = tmp; continue; case 'l': output_tab_width = get_nonnegative(optarg, "output tab width must be non-negative", 1); continue; case 'm': grok_mail_headers = 1; continue; case 'n': format_troff = 1; continue; case 'p': allow_indented_paragraphs = 1; continue; case 's': coalesce_spaces_P = 1; continue; case 't': tab_width = get_positive(optarg, "tab width must be positive", 1); continue; case 'w': goal_length = get_positive(optarg, "width must be positive", 1); max_length = goal_length; continue; 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; } continue; case 'h': default: fprintf(stderr, "usage: fmt [-cmps] [-d chars] [-l num] [-t num]\n" " [-w width | -width | goal [maximum]] [file ...]\n" "Options: -c center each line instead of formatting\n" " -d <chars> double-space after <chars> at line end\n" " -l <n> turn each <n> spaces at start of line into a tab\n" " -m try to make sure mail header lines stay separate\n" " -n format lines beginning with a dot\n" " -p allow indented paragraphs\n" " -s coalesce whitespace inside lines\n" " -t <n> have tabs every <n> columns\n" " -w <n> set maximum width to <n>\n" " goal set target width to goal\n"); exit(ch == 'h' ? 0 : EX_USAGE); } 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(EX_USAGE, "max length must be >= goal length"); } } if (goal_length == 0) goal_length = 65; if (max_length == 0) max_length = goal_length + 10; if (max_length >= SIZE_T_MAX / sizeof(wchar_t)) errx(EX_USAGE, "max length too large"); /* really needn't be longer */ output_buffer = XMALLOC((max_length + 1) * sizeof(wchar_t)); /* 2. Process files. */ if (argc > 0) { while (argc-- > 0) process_named_file(*argv++); } else { process_stream(stdin, "standard input"); } /* We're done. */ return n_errors ? EX_NOINPUT : 0; } /* Process a single file, given its name. */ static void process_named_file(const char *name) { FILE *f = fopen(name, "r"); if (!f) { warn("%s", name); ++n_errors; } else { process_stream(f, name); if (ferror(f)) { warn("%s", name); ++n_errors; } 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) { 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 */ HdrType prev_header_type = hdr_ParagraphStart; /* ^-- header_type of previous line; -1 at para start */ wchar_t *line; size_t length; if (centerP) { center_stream(stream, name); return; } while ((line = get_line(stream, &length)) != NULL) { size_t np = indent_length(line, length); { HdrType 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 (and we don't * format troff), 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 (length == 0 || (line[0] == '.' && !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(output_in_paragraph ? last_indent : first_indent, np); para_line_number = 0; first_indent = np; last_indent = np; if (header_type == hdr_Header) last_indent = 2; /* for cont. lines */ if (length == 0 || (line[0] == '.' && !format_troff)) { if (length == 0) putwchar('\n'); else wprintf(L"%.*ls\n", (int)length, line); 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; } { size_t n = np; while (n < length) { /* Find word end and count spaces after it */ size_t word_length = 0, space_length = 0; while (n + word_length < length && line[n + word_length] != ' ') ++word_length; space_length = word_length; while (n + space_length < length && line[n + space_length] == ' ') ++space_length; /* Send the word to the output machinery. */ output_word(first_indent, last_indent, line + n, word_length, space_length - word_length); n += space_length; } } ++para_line_number; } new_paragraph(output_in_paragraph ? last_indent : first_indent, 0); if (ferror(stream)) { warn("%s", name); ++n_errors; } } /* How long is the indent on this line? */ static size_t indent_length(const wchar_t *line, size_t length) { size_t n = 0; while (n < length && *line++ == ' ') ++n; 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 wchar_t *line) { if (!iswupper(*line++)) return 0; while (*line && (iswalnum(*line) || *line == '-')) ++line; return (*line == ':' && iswspace(line[1])); } /* Begin a new paragraph with an indent of |indent| spaces. */ static void new_paragraph(size_t old_indent, size_t indent) { if (output_buffer_length) { if (old_indent > 0) output_indent(old_indent); wprintf(L"%.*ls\n", (int)output_buffer_length, output_buffer); } x = indent; x0 = 0; output_buffer_length = 0; pending_spaces = 0; output_in_paragraph = 0; } /* Output spaces or tabs for leading indentation. */ static void output_indent(size_t n_spaces) { if (output_tab_width) { while (n_spaces >= output_tab_width) { putwchar('\t'); n_spaces -= output_tab_width; } } while (n_spaces-- > 0) putwchar(' '); } /* Output a single word, or add it to the buffer. * 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 wchar_t *word, size_t length, size_t spaces) { size_t new_x; size_t indent = output_in_paragraph ? indent1 : indent0; size_t width; const wchar_t *p; int cwidth; for (p = word, width = 0; p < &word[length]; p++) width += (cwidth = wcwidth(*p)) > 0 ? cwidth : 1; 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 = wcschr(sentence_enders, word[length - 1]) ? 2 : 1; if (new_x <= goal_length) { /* * After adding the word we still aren't at the goal length, * so clearly we add it to the buffer rather than outputting * it. */ wmemset(output_buffer + output_buffer_length, L' ', pending_spaces); x0 += pending_spaces; x += pending_spaces; output_buffer_length += pending_spaces; wmemcpy(output_buffer + output_buffer_length, word, length); x0 += width; x += width; output_buffer_length += length; pending_spaces = spaces; } else { /* * Adding the word takes us past the goal. Print the * line-so-far, and the word too iff either (1) the lsf is * empty or (2) that makes us nearer the goal but doesn't * take us over the limit, or (3) the word on its own takes * us over the limit. In case (3) we put a newline in * between. */ if (indent > 0) output_indent(indent); wprintf(L"%.*ls", (int)output_buffer_length, output_buffer); if (x0 == 0 || (new_x <= max_length && new_x - goal_length <= goal_length - x)) { wprintf(L"%*ls", (int)pending_spaces, L""); goto write_out_word; } else { /* * If the word takes us over the limit on its own, * just spit it out and don't bother buffering it. */ if (indent + width > max_length) { putwchar('\n'); if (indent > 0) output_indent(indent); write_out_word: wprintf(L"%.*ls", (int)length, word); x0 = 0; x = indent1; pending_spaces = 0; output_buffer_length = 0; } else { wmemcpy(output_buffer, word, length); x0 = width; x = width + indent1; pending_spaces = spaces; output_buffer_length = length; } } putwchar('\n'); 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) { wchar_t *line, *p; size_t length; size_t width; int cwidth; while ((line = get_line(stream, &length)) != NULL) { size_t l = length; while (l > 0 && iswspace(*line)) { ++line; --l; } length = l; for (p = line, width = 0; p < &line[length]; p++) width += (cwidth = wcwidth(*p)) > 0 ? cwidth : 1; l = width; while (l < goal_length) { putwchar(' '); l += 2; } wprintf(L"%.*ls\n", (int)length, line); } if (ferror(stream)) { warn("%s", name); ++n_errors; } } /* Get a single line from a stream. Expand tabs, strip control * characters and trailing whitespace, and handle backspaces. * Return the address of the buffer containing the line, and * put the length of the line in |lengthp|. * 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 0. * Don't confuse |spaces_pending| here with the global * |pending_spaces|. */ static wchar_t * get_line(FILE *stream, size_t *lengthp) { static wchar_t *buf = NULL; static size_t length = 0; size_t len = 0; wint_t ch; size_t spaces_pending = 0; int troff = 0; size_t col = 0; int cwidth; if (buf == NULL) { length = 100; buf = XMALLOC(length * sizeof(wchar_t)); } while ((ch = getwc(stream)) != '\n' && ch != WEOF) { if (len + spaces_pending == 0 && ch == '.' && !format_troff) troff = 1; if (ch == ' ') ++spaces_pending; else if (troff || iswprint(ch)) { while (len + spaces_pending >= length) { length *= 2; buf = xrealloc(buf, length * sizeof(wchar_t)); } while (spaces_pending > 0) { --spaces_pending; buf[len++] = ' '; col++; } buf[len++] = ch; col += (cwidth = wcwidth(ch)) > 0 ? cwidth : 1; } else if (ch == '\t') spaces_pending += tab_width - (col + spaces_pending) % tab_width; else if (ch == '\b') { if (len) --len; if (col) --col; } } *lengthp = len; return (len > 0 || ch != WEOF) ? buf : 0; } /* (Re)allocate some memory, exiting with an error if we can't. */ static void * xrealloc(void *ptr, size_t nbytes) { void *p = realloc(ptr, nbytes); if (p == NULL) errx(EX_OSERR, "out of memory"); return p; }
