/* $OpenBSD: fold.c,v 1.18 2016/05/23 10:31:42 schwarze Exp $ */ /* $NetBSD: fold.c,v 1.6 1995/09/01 01:42:44 jtc Exp $ */ /*- * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Kevin Ruddy. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #define DEFLINEWIDTH 80 static void fold(unsigned int); static int isu8cont(unsigned char); static __dead void usage(void); int count_bytes = 0; int split_words = 0; int main(int argc, char *argv[]) { int ch, lastch, newarg, prevoptind; unsigned int width; const char *errstr; setlocale(LC_CTYPE, ""); if (pledge("stdio rpath", NULL) == -1) err(1, "pledge"); width = 0; lastch = '\0'; prevoptind = 1; newarg = 1; while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1) { switch (ch) { case 'b': count_bytes = 1; break; case 's': split_words = 1; break; case 'w': width = strtonum(optarg, 1, UINT_MAX, &errstr); if (errstr != NULL) errx(1, "illegal width value, %s: %s", errstr, optarg); break; case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': if (newarg) width = 0; else if (!isdigit(lastch)) usage(); if (width > UINT_MAX / 10 - 1) errx(1, "illegal width value, too large"); width = (width * 10) + (ch - '0'); if (width < 1) errx(1, "illegal width value, too small"); break; default: usage(); } lastch = ch; newarg = optind != prevoptind; prevoptind = optind; } argv += optind; argc -= optind; if (width == 0) width = DEFLINEWIDTH; if (!*argv) { if (pledge("stdio", NULL) == -1) err(1, "pledge"); fold(width); } else { for (; *argv; ++argv) { if (!freopen(*argv, "r", stdin)) err(1, "%s", *argv); else fold(width); } } return 0; } /* * Fold the contents of standard input to fit within WIDTH columns * (or bytes) and write to standard output. * * If split_words is set, split the line at the last space character * on the line. This flag necessitates storing the line in a buffer * until the current column > width, or a newline or EOF is read. * * The buffer can grow larger than WIDTH due to backspaces and carriage * returns embedded in the input stream. */ static void fold(unsigned int max_width) { static char *buf = NULL; static size_t bufsz = 2048; char *cp; /* Current mb character. */ char *np; /* Next mb character. */ char *sp; /* To search for the last space. */ char *nbuf; /* For buffer reallocation. */ wchar_t wc; /* Current wide character. */ int ch; /* Last byte read. */ int len; /* Bytes in the current mb character. */ unsigned int col; /* Current display position. */ int width; /* Display width of wc. */ if (buf == NULL && (buf = malloc(bufsz)) == NULL) err(1, NULL); np = cp = buf; ch = 0; col = 0; while (ch != EOF) { /* Loop on input characters. */ while ((ch = getchar()) != EOF) { /* Loop on input bytes. */ if (np + 1 == buf + bufsz) { nbuf = reallocarray(buf, 2, bufsz); if (nbuf == NULL) err(1, NULL); bufsz *= 2; cp = nbuf + (cp - buf); np = nbuf + (np - buf); buf = nbuf; } *np++ = ch; /* * Read up to and including the first byte of * the next character, such that we are sure * to have a complete character in the buffer. * There is no need to read more than five bytes * ahead, since UTF-8 characters are four bytes * long at most. */ if (np - cp > 4 || (np - cp > 1 && !isu8cont(ch))) break; } while (cp < np) { /* Loop on output characters. */ /* Handle end of line and backspace. */ if (*cp == '\n' || (*cp == '\r' && !count_bytes)) { fwrite(buf, 1, ++cp - buf, stdout); memmove(buf, cp, np - cp); np = buf + (np - cp); cp = buf; col = 0; continue; } if (*cp == '\b' && !count_bytes) { if (col) col--; cp++; continue; } /* * Measure display width. * Process the last byte only if * end of file was reached. */ if (np - cp > (ch != EOF)) { len = 1; width = 1; if (*cp == '\t') { if (count_bytes == 0) width = 8 - (col & 7); } else if ((len = mbtowc(&wc, cp, np - cp)) < 1) len = 1; else if (count_bytes) width = len; else if ((width = wcwidth(wc)) < 0) width = 1; col += width; if (col <= max_width || cp == buf) { cp += len; continue; } } /* Line break required. */ if (col > max_width) { if (split_words) { for (sp = cp; sp > buf; sp--) { if (sp[-1] == ' ') { cp = sp; break; } } } fwrite(buf, 1, cp - buf, stdout); putchar('\n'); memmove(buf, cp, np - cp); np = buf + (np - cp); cp = buf; col = 0; continue; } /* Need more input. */ break; } } fwrite(buf, 1, np - buf, stdout); if (ferror(stdin)) err(1, NULL); } static int isu8cont(unsigned char c) { return MB_CUR_MAX > 1 && (c & (0x80 | 0x40)) == 0x80; } static __dead void usage(void) { (void)fprintf(stderr, "usage: fold [-bs] [-w width] [file ...]\n"); exit(1); }