/* Word-wrapping and line-truncating streams Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc. This file is part of the GNU C Library. Written by Miles Bader <miles@gnu.ai.mit.edu>. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU C Library 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* This package emulates glibc `line_wrap_stream' semantics for systems that don't have that. */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #include <stdlib.h> #include <string.h> #include <errno.h> #include <stdarg.h> #include <ctype.h> #include "argp-fmtstream.h" #include "argp-namefrob.h" #ifndef ARGP_FMTSTREAM_USE_LINEWRAP #ifndef isblank #define isblank(ch) ((ch)==' ' || (ch)=='\t') #endif #if defined _LIBC && defined USE_IN_LIBIO # include <libio/libioP.h> # define __vsnprintf(s, l, f, a) _IO_vsnprintf (s, l, f, a) #endif #define INIT_BUF_SIZE 200 #define PRINTF_SIZE_GUESS 150 /* Return an argp_fmtstream that outputs to STREAM, and which prefixes lines written on it with LMARGIN spaces and limits them to RMARGIN columns total. If WMARGIN >= 0, words that extend past RMARGIN are wrapped by replacing the whitespace before them with a newline and WMARGIN spaces. Otherwise, chars beyond RMARGIN are simply dropped until a newline. Returns NULL if there was an error. */ argp_fmtstream_t __argp_make_fmtstream (FILE *stream, size_t lmargin, size_t rmargin, ssize_t wmargin) { argp_fmtstream_t fs = malloc (sizeof (struct argp_fmtstream)); if (fs) { fs->stream = stream; fs->lmargin = lmargin; fs->rmargin = rmargin; fs->wmargin = wmargin; fs->point_col = 0; fs->point_offs = 0; fs->buf = malloc (INIT_BUF_SIZE); if (! fs->buf) { free (fs); fs = 0; } else { fs->p = fs->buf; fs->end = fs->buf + INIT_BUF_SIZE; } } return fs; } #ifdef weak_alias weak_alias (__argp_make_fmtstream, argp_make_fmtstream) #endif /* Flush FS to its stream, and free it (but don't close the stream). */ void __argp_fmtstream_free (argp_fmtstream_t fs) { __argp_fmtstream_update (fs); if (fs->p > fs->buf) fwrite_unlocked (fs->buf, 1, fs->p - fs->buf, fs->stream); free (fs->buf); free (fs); } #ifdef weak_alias weak_alias (__argp_fmtstream_free, argp_fmtstream_free) #endif /* Process FS's buffer so that line wrapping is done from POINT_OFFS to the end of its buffer. This code is mostly from glibc stdio/linewrap.c. */ void __argp_fmtstream_update (argp_fmtstream_t fs) { char *buf, *nl; size_t len; /* Scan the buffer for newlines. */ buf = fs->buf + fs->point_offs; while (buf < fs->p) { size_t r; if (fs->point_col == 0 && fs->lmargin != 0) { /* We are starting a new line. Print spaces to the left margin. */ const size_t pad = fs->lmargin; if (fs->p + pad < fs->end) { /* We can fit in them in the buffer by moving the buffer text up and filling in the beginning. */ memmove (buf + pad, buf, fs->p - buf); fs->p += pad; /* Compensate for bigger buffer. */ memset (buf, ' ', pad); /* Fill in the spaces. */ buf += pad; /* Don't bother searching them. */ } else { /* No buffer space for spaces. Must flush. */ size_t i; for (i = 0; i < pad; i++) putc_unlocked (' ', fs->stream); } fs->point_col = pad; } len = fs->p - buf; nl = memchr (buf, '\n', len); if (fs->point_col < 0) fs->point_col = 0; if (!nl) { /* The buffer ends in a partial line. */ if (fs->point_col + len < fs->rmargin) { /* The remaining buffer text is a partial line and fits within the maximum line width. Advance point for the characters to be written and stop scanning. */ fs->point_col += len; break; } else /* Set the end-of-line pointer for the code below to the end of the buffer. */ nl = fs->p; } else if (fs->point_col + (nl - buf) < (ssize_t) fs->rmargin) { /* The buffer contains a full line that fits within the maximum line width. Reset point and scan the next line. */ fs->point_col = 0; buf = nl + 1; continue; } /* This line is too long. */ r = fs->rmargin - 1; if (fs->wmargin < 0) { /* Truncate the line by overwriting the excess with the newline and anything after it in the buffer. */ if (nl < fs->p) { memmove (buf + (r - fs->point_col), nl, fs->p - nl); fs->p -= buf + (r - fs->point_col) - nl; /* Reset point for the next line and start scanning it. */ fs->point_col = 0; buf += r + 1; /* Skip full line plus \n. */ } else { /* The buffer ends with a partial line that is beyond the maximum line width. Advance point for the characters written, and discard those past the max from the buffer. */ fs->point_col += len; fs->p -= fs->point_col - r; break; } } else { /* Do word wrap. Go to the column just past the maximum line width and scan back for the beginning of the word there. Then insert a line break. */ char *p, *nextline; int i; p = buf + (r + 1 - fs->point_col); while (p >= buf && !isblank (*p)) --p; nextline = p + 1; /* This will begin the next line. */ if (nextline > buf) { /* Swallow separating blanks. */ if (p >= buf) do --p; while (p >= buf && isblank (*p)); nl = p + 1; /* The newline will replace the first blank. */ } else { /* A single word that is greater than the maximum line width. Oh well. Put it on an overlong line by itself. */ p = buf + (r + 1 - fs->point_col); /* Find the end of the long word. */ do ++p; while (p < nl && !isblank (*p)); if (p == nl) { /* It already ends a line. No fussing required. */ fs->point_col = 0; buf = nl + 1; continue; } /* We will move the newline to replace the first blank. */ nl = p; /* Swallow separating blanks. */ do ++p; while (isblank (*p)); /* The next line will start here. */ nextline = p; } /* Note: There are a bunch of tests below for NEXTLINE == BUF + LEN + 1; this case is where NL happens to fall at the end of the buffer, and NEXTLINE is in fact empty (and so we need not be careful to maintain its contents). */ if (nextline == buf + len + 1 ? fs->end - nl < fs->wmargin + 1 : nextline - (nl + 1) < fs->wmargin) { /* The margin needs more blanks than we removed. */ if (fs->end - fs->p > fs->wmargin + 1) /* Make some space for them. */ { size_t mv = fs->p - nextline; memmove (nl + 1 + fs->wmargin, nextline, mv); nextline = nl + 1 + fs->wmargin; len = nextline + mv - buf; *nl++ = '\n'; } else /* Output the first line so we can use the space. */ { if (nl > fs->buf) fwrite_unlocked (fs->buf, 1, nl - fs->buf, fs->stream); putc_unlocked ('\n', fs->stream); len += buf - fs->buf; nl = buf = fs->buf; } } else /* We can fit the newline and blanks in before the next word. */ *nl++ = '\n'; if (nextline - nl >= fs->wmargin || (nextline == buf + len + 1 && fs->end - nextline >= fs->wmargin)) /* Add blanks up to the wrap margin column. */ for (i = 0; i < fs->wmargin; ++i) *nl++ = ' '; else for (i = 0; i < fs->wmargin; ++i) putc_unlocked (' ', fs->stream); /* Copy the tail of the original buffer into the current buffer position. */ if (nl < nextline) memmove (nl, nextline, buf + len - nextline); len -= nextline - buf; /* Continue the scan on the remaining lines in the buffer. */ buf = nl; /* Restore bufp to include all the remaining text. */ fs->p = nl + len; /* Reset the counter of what has been output this line. If wmargin is 0, we want to avoid the lmargin getting added, so we set point_col to a magic value of -1 in that case. */ fs->point_col = fs->wmargin ? fs->wmargin : -1; } } /* Remember that we've scanned as far as the end of the buffer. */ fs->point_offs = fs->p - fs->buf; } /* Ensure that FS has space for AMOUNT more bytes in its buffer, either by growing the buffer, or by flushing it. True is returned iff we succeed. */ int __argp_fmtstream_ensure (struct argp_fmtstream *fs, size_t amount) { if ((size_t) (fs->end - fs->p) < amount) { ssize_t wrote; /* Flush FS's buffer. */ __argp_fmtstream_update (fs); wrote = fwrite_unlocked (fs->buf, 1, fs->p - fs->buf, fs->stream); if (wrote == fs->p - fs->buf) { fs->p = fs->buf; fs->point_offs = 0; } else { fs->p -= wrote; fs->point_offs -= wrote; memmove (fs->buf, fs->buf + wrote, fs->p - fs->buf); return 0; } if ((size_t) (fs->end - fs->buf) < amount) /* Gotta grow the buffer. */ { size_t new_size = fs->end - fs->buf + amount; char *new_buf = realloc (fs->buf, new_size); if (! new_buf) { __set_errno (ENOMEM); return 0; } fs->buf = new_buf; fs->end = new_buf + new_size; fs->p = fs->buf; } } return 1; } ssize_t __argp_fmtstream_printf (struct argp_fmtstream *fs, const char *fmt, ...) { int out; size_t avail; size_t size_guess = PRINTF_SIZE_GUESS; /* How much space to reserve. */ do { va_list args; if (! __argp_fmtstream_ensure (fs, size_guess)) return -1; va_start (args, fmt); avail = fs->end - fs->p; out = __vsnprintf (fs->p, avail, fmt, args); va_end (args); if (out >= avail) size_guess = out + 1; } while (out >= avail); fs->p += out; return out; } #ifdef weak_alias weak_alias (__argp_fmtstream_printf, argp_fmtstream_printf) #endif #endif /* !ARGP_FMTSTREAM_USE_LINEWRAP */