X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=string.c;h=38e25b09c5f3ff2b289d6e943a0f7bde3bfc23ad;hp=c22dc7cfce51954c65ecd407857e0352b09a53f3;hb=4ec04c614fc2e835a2d106ee61482ba0c729f5e6;hpb=d1f0f00fdedf1254b7e4119d8148a0da37b12a23 diff --git a/string.c b/string.c index c22dc7cf..38e25b09 100644 --- a/string.c +++ b/string.c @@ -6,12 +6,18 @@ /** \file string.c Memory allocation and string handling functions. */ -#include /* gettimeofday */ +#define _GNU_SOURCE + #include #include /* uname() */ + #include #include +#include +#include +#include + #include "para.h" #include "string.h" #include "error.h" @@ -136,15 +142,18 @@ __must_check __malloc char *para_strdup(const char *s) __printf_2_0 unsigned xvasprintf(char **result, const char *fmt, va_list ap) { int ret; - size_t size; + size_t size = 150; va_list aq; + *result = para_malloc(size + 1); va_copy(aq, ap); - ret = vsnprintf(NULL, 0, fmt, aq); + ret = vsnprintf(*result, size, fmt, aq); va_end(aq); assert(ret >= 0); + if (ret < size) /* OK */ + return ret; size = ret + 1; - *result = para_malloc(size); + *result = para_realloc(*result, size); va_copy(aq, ap); ret = vsnprintf(*result, size, fmt, aq); va_end(aq); @@ -370,10 +379,10 @@ __malloc char *para_hostname(void) * incomplete line) is moved to the beginning of the buffer if FELF_READ_ONLY is * unset. * - * \return If \p FELF_READ_ONLY is not set in \a flags, this function returns - * the number of bytes not handled to \p line_handler, otherwise the number of - * complete lines. On errors the negative error code of the \p line_handler is - * returned. + * \return On success this function returns the number of bytes not handled to + * \p line_handler. The only possible error is a negative return value from the + * line handler. In this case processing stops and the return value of the line + * handler is returned to indicate failure. * * \sa \ref for_each_line_flags. */ @@ -399,26 +408,25 @@ int for_each_line(unsigned flags, char *buf, size_t size, } else end = next_cr; num_lines++; - if (flags & FELF_READ_ONLY) { - size_t s = end - start; - char *b = para_malloc(s + 1); - memcpy(b, start, s); - b[s] = '\0'; -// PARA_NOTICE_LOG("b: %s, start: %s\n", b, start); - ret = line_handler(b, private_data); - free(b); - } else { - *end = '\0'; - ret = line_handler(start, private_data); + if (!(flags & FELF_DISCARD_FIRST) || start != buf) { + if (flags & FELF_READ_ONLY) { + size_t s = end - start; + char *b = para_malloc(s + 1); + memcpy(b, start, s); + b[s] = '\0'; + ret = line_handler(b, private_data); + free(b); + } else { + *end = '\0'; + ret = line_handler(start, private_data); + } + if (ret < 0) + return ret; } - if (ret < 0) - return ret; start = ++end; } - if (flags & FELF_READ_ONLY) - return num_lines; i = buf + size - start; - if (i && i != size) + if (i && i != size && !(flags & FELF_READ_ONLY)) memmove(buf, start, i); return i; } @@ -943,3 +951,145 @@ char *key_value_copy(const char *src, size_t len, const char *key) return NULL; return safe_strdup(src + keylen + 1, len - keylen - 1); } + +static bool utf8_mode(void) +{ + static bool initialized, have_utf8; + + if (!initialized) { + char *info = nl_langinfo(CODESET); + have_utf8 = (info && strcmp(info, "UTF-8") == 0); + initialized = true; + PARA_INFO_LOG("%susing UTF-8 character encoding\n", + have_utf8? "" : "not "); + } + return have_utf8; +} + +/* + * glibc's wcswidth returns -1 if the string contains a tab character, which + * makes the function next to useless. The two functions below are taken from + * mutt. + */ + +#define IsWPrint(wc) (iswprint(wc) || wc >= 0xa0) + +static int mutt_wcwidth(wchar_t wc, size_t pos) +{ + int n; + + if (wc == 0x09) /* tab */ + return (pos | 7) + 1 - pos; + n = wcwidth(wc); + if (IsWPrint(wc) && n > 0) + return n; + if (!(wc & ~0x7f)) + return 2; + if (!(wc & ~0xffff)) + return 6; + return 10; +} + +static size_t mutt_wcswidth(const wchar_t *s, size_t n) +{ + size_t w = 0; + + while (n--) + w += mutt_wcwidth(*s++, w); + return w; +} + +/** + * Skip a given number of cells at the beginning of a string. + * + * \param s The input string. + * \param cells_to_skip Desired number of cells that should be skipped. + * \param bytes_to_skip Result. + * + * This function computes how many input bytes must be skipped to advance a + * string by the given width. If the current character encoding is not UTF-8, + * this is simply the given number of cells, i.e. \a cells_to_skip. Otherwise, + * \a s is treated as a multibyte string and on successful return, \a s + + * bytes_to_skip points to the start of a multibyte string such that the total + * width of the multibyte characters that are skipped by advancing \a s that + * many bytes equals at least \a cells_to_skip. + * + * \return Standard. + */ +int skip_cells(const char *s, size_t cells_to_skip, size_t *bytes_to_skip) +{ + wchar_t wc; + mbstate_t ps; + size_t n, bytes_parsed, cells_skipped; + + *bytes_to_skip = 0; + if (cells_to_skip == 0) + return 0; + if (!utf8_mode()) { + *bytes_to_skip = cells_to_skip; + return 0; + } + bytes_parsed = cells_skipped = 0; + memset(&ps, 0, sizeof(ps)); + n = strlen(s); + while (cells_to_skip > cells_skipped) { + size_t mbret; + + mbret = mbrtowc(&wc, s + bytes_parsed, n - bytes_parsed, &ps); + assert(mbret != 0); + if (mbret == (size_t)-1 || mbret == (size_t)-2) + return -ERRNO_TO_PARA_ERROR(EILSEQ); + bytes_parsed += mbret; + cells_skipped += mutt_wcwidth(wc, cells_skipped); + } + *bytes_to_skip = bytes_parsed; + return 1; +} + +/** + * Compute the width of an UTF-8 string. + * + * \param s The string. + * \param result The width of \a s is returned here. + * + * If not in UTF8-mode. this function is just a wrapper for strlen(3). + * Otherwise \a s is treated as an UTF-8 string and its display width is + * computed. Note that this function may fail if the underlying call to + * mbsrtowcs(3) fails, so the caller must check the return value. + * + * \sa nl_langinfo(3), wcswidth(3). + * + * \return Standard. + */ +__must_check int strwidth(const char *s, size_t *result) +{ + const char *src = s; + mbstate_t state; + static wchar_t *dest; + size_t num_wchars; + + /* + * Never call any log function here. This may result in an endless loop + * as para_gui's para_log() calls this function. + */ + + if (!utf8_mode()) { + *result = strlen(s); + return 0; + } + memset(&state, 0, sizeof(state)); + *result = 0; + num_wchars = mbsrtowcs(NULL, &src, 0, &state); + if (num_wchars == (size_t)-1) + return -ERRNO_TO_PARA_ERROR(errno); + if (num_wchars == 0) + return 0; + dest = para_malloc(num_wchars * sizeof(*dest)); + src = s; + memset(&state, 0, sizeof(state)); + num_wchars = mbsrtowcs(dest, &src, num_wchars, &state); + assert(num_wchars > 0 && num_wchars != (size_t)-1); + *result = mutt_wcswidth(dest, num_wchars); + free(dest); + return 1; +}