X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/mLib/blobdiff_plain/dd3c57bc8cac59e0d657ee665ce462988d27d714..18c831dcd0ae4d660c70ccac69d27ed2a97851be:/struct/dstr.h diff --git a/struct/dstr.h b/struct/dstr.h new file mode 100644 index 0000000..3ef3051 --- /dev/null +++ b/struct/dstr.h @@ -0,0 +1,319 @@ +/* -*-c-*- + * + * Handle dynamically growing strings + * + * (c) 1998 Straylight/Edgeware + */ + +/*----- Licensing notice --------------------------------------------------* + * + * This file is part of the mLib utilities library. + * + * mLib 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. + * + * mLib 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 mLib; if not, write to the Free + * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, + * MA 02111-1307, USA. + */ + +#ifndef MLIB_DSTR_H +#define MLIB_DSTR_H + +#ifdef __cplusplus + extern "C" { +#endif + +/*----- Rationale ---------------------------------------------------------* + * + * This file declares what is hopefully a fairly useful collection of + * primitive string handling functions. The idea is that the strings + * allocate memory for themselves as required. The @dstr@ routines don't + * assume any sort of terminator character, so arbitrary binary data can + * be stored in a dynamic string. With luck, this should put a stop to + * any buffer overflow problems. + */ + +/*----- Header files ------------------------------------------------------*/ + +#include +#include +#include + +#ifndef MLIB_ALLOC_H +# include "alloc.h" +#endif + +#ifndef MLIB_ARENA_H +# include "arena.h" +#endif + +/*----- Data structures ---------------------------------------------------*/ + +typedef struct dstr { + char *buf; /* Pointer to string buffer */ + size_t sz; /* Size of the buffer */ + size_t len; /* Length of the string */ + arena *a; /* Pointer to arena */ +} dstr; + +#define DSTR_INIT { 0, 0, 0, &arena_stdlib } /* How to initialize one */ + +/*----- Functions provided ------------------------------------------------*/ + +/* --- @dstr_create@ --- * + * + * Arguments: @dstr *d@ = pointer to a dynamic string block + * + * Returns: --- + * + * Use: Initializes a dynamic string. + */ + +extern void dstr_create(dstr */*d*/); + +#define DCREATE(d) do { \ + dstr *_dd = (d); \ + _dd->buf = 0; \ + _dd->sz = 0; \ + _dd->len = 0; \ + _dd->a = &arena_stdlib; \ +} while (0) + +/* --- @dstr_destroy@ --- * + * + * Arguments: @dstr *d@ = pointer to a dynamic string block + * + * Returns: --- + * + * Use: Reclaims the space used by a dynamic string. + */ + +extern void dstr_destroy(dstr */*d*/); + +#define DDESTROY(d) do { \ + dstr *_d = (d); \ + if (_d->buf) \ + x_free(_d->a, _d->buf); \ + DCREATE(_d); \ +} while (0) + +/* --- @dstr_reset@ --- * + * + * Arguments: @dstr *d@ = pointer to a dynamic string block + * + * Returns: --- + * + * Use: Resets a string so that new data gets put at the beginning. + */ + +extern void dstr_reset(dstr */*d*/); + +#define DRESET(d) ((d)->len = 0) + +/* --- @dstr_ensure@ --- * + * + * Arguments: @dstr *d@ = pointer to a dynamic string block + * @size_t sz@ = amount of free space to ensure + * + * Returns: --- + * + * Use: Ensures that at least @sz@ bytes are available in the + * given string. + */ + +extern void dstr_ensure(dstr */*d*/, size_t /*sz*/); + +#define DENSURE(d, rq) do { \ + dstr *_dd = (d); \ + size_t _rq = (rq); \ + if (_dd->len + _rq > _dd->sz) dstr_ensure(_dd, _rq); \ +} while (0) + +/* --- @dstr_putc@ --- * + * + * Arguments: @dstr *d@ = pointer to a dynamic string block + * @char ch@ = character to append + * + * Returns: --- + * + * Use: Appends a character to a string. + */ + +extern void dstr_putc(dstr */*d*/, char /*ch*/); + +#define DPUTC(d, ch) do { \ + dstr *_d = (d); \ + DENSURE(_d, 1); \ + _d->buf[_d->len++] = (ch); \ +} while (0) + +/* --- @dstr_putz@ --- * + * + * Arguments: @dstr *d@ = pointer to a dynamic string block + * + * Returns: --- + * + * Use: Appends a null byte to a string. The null byte does not + * contribute to the string's length, and will be overwritten + * by subsequent `put' operations. + */ + +extern void dstr_putz(dstr */*d*/); + +#define DPUTZ(d) do { \ + dstr *_d = (d); \ + DENSURE(_d, 1); \ + _d->buf[_d->len] = 0; \ +} while (0) + +/* --- @dstr_puts@ --- * + * + * Arguments: @dstr *d@ = pointer to a dynamic string block + * @const char *s@ = pointer to string to append + * + * Returns: --- + * + * Use: Appends a character string to a string. A trailing null + * byte is added, as for @dstr_putz@. + */ + +extern void dstr_puts(dstr */*d*/, const char */*s*/); + +#define DPUTS(d, s) do { \ + dstr *_d = (d); \ + const char *_s = (s); \ + size_t _sz = strlen(_s); \ + DENSURE(_d, _sz + 1); \ + memcpy(_d->buf + _d->len, _s, _sz + 1); \ + _d->len += _sz; \ +} while (0) + +/* --- @dstr_vputf@ --- * + * + * Arguments: @dstr *d@ = pointer to a dynamic string block + * @const char *p@ = pointer to @printf@-style format string + * @va_list *ap@ = argument handle + * + * Returns: The number of characters written to the string. + * + * Use: As for @dstr_putf@, but may be used as a back-end to user- + * supplied functions with @printf@-style interfaces. + */ + +extern int dstr_vputf(dstr */*d*/, const char */*p*/, va_list */*ap*/); + +/* --- @dstr_putf@ --- * + * + * Arguments: @dstr *d@ = pointer to a dynamic string block + * @const char *p@ = pointer to @printf@-style format string + * @...@ = argument handle + * + * Returns: The number of characters written to the string. + * + * Use: Writes a piece of text to a dynamic string, doing @printf@- + * style substitutions as it goes. Intended to be robust if + * faced with malicious arguments, but not if the format string + * itself is malicious. + */ + +extern int dstr_putf(dstr */*d*/, const char */*p*/, ...); + +/* --- @dstr_putd@ --- * + * + * Arguments: @dstr *d@ = pointer to a dynamic string block + * @const dstr *s@ = pointer to a dynamic string to append + * + * Returns: --- + * + * Use: Appends a dynamic string to a string. A trailing null + * byte is added, as for @dstr_putz@. + */ + +extern void dstr_putd(dstr */*d*/, const dstr */*s*/); + +#define DPUTD(d, s) do { \ + dstr *_d = (d); \ + const dstr *_s = (s); \ + DENSURE(_d, _s->len + 1); \ + memcpy(_d->buf + _d->len, _s->buf, _s->len); \ + _d->len += _s->len; \ + _d->buf[_d->len] = 0; \ +} while (0) + +/* --- @dstr_putm@ --- * + * + * Arguments: @dstr *d@ = pointer to a dynamic string block + * @const void *p@ = pointer to a block to append + * @size_t sz@ = size of the block + * + * Returns: Appends an arbitrary data block to a string. No trailing + * null is appended. + */ + +extern void dstr_putm(dstr */*d*/, const void */*p*/, size_t /*sz*/); + +#define DPUTM(d, p, sz) do { \ + dstr *_d = (d); \ + size_t _sz = (sz); \ + DENSURE(_d, _sz); \ + memcpy(_d->buf + _d->len, (p), _sz); \ + _d->len += _sz; \ +} while (0) + +/* --- @dstr_tidy@ --- * + * + * Arguments: @dstr *d@ = pointer to a dynamic string block + * + * Returns: --- + * + * Use: Reduces the amount of memory used by a string. A trailing + * null byte is added, as for @dstr_putz@. + */ + +extern void dstr_tidy(dstr */*d*/); + +/* --- @dstr_putline@ --- * + * + * Arguments: @dstr *d@ = pointer to a dynamic string block + * @FILE *fp@ = a stream to read from + * + * Returns: The number of characters read into the buffer, or @EOF@ if + * end-of-file was reached before any characters were read. + * + * Use: Appends the next line from the given input stream to the + * string. A trailing newline is not added; a trailing null + * byte is appended, as for @dstr_putz@. + */ + +extern int dstr_putline(dstr */*d*/, FILE */*fp*/); + +/* --- @dstr_write@ --- * + * + * Arguments: @dstr *d@ = pointer to a dynamic string block + * @FILE *fp@ = a stream to write on + * + * Returns: The number of bytes written (as for @fwrite@). + * + * Use: Writes a dynamic string to a file. + */ + +extern size_t dstr_write(const dstr */*d*/, FILE */*fp*/); + +#define DWRITE(d, fp) fwrite((d)->buf, 1, (d)->len, (fp)) + +/*----- That's all, folks -------------------------------------------------*/ + +#ifdef __cplusplus + } +#endif + +#endif