diff options
| -rw-r--r-- | extra/Configs/Config.in | 11 | ||||
| -rw-r--r-- | libc/misc/time/time.c | 44 |
2 files changed, 52 insertions, 3 deletions
diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in index 21c14acf4..680365980 100644 --- a/extra/Configs/Config.in +++ b/extra/Configs/Config.in @@ -848,6 +848,17 @@ config UCLIBC_TZ_FILE_PATH Most people will use the default of '/etc/TZ'. +config UCLIBC_FALLBACK_TO_ETC_LOCALTIME + bool "Use /etc/localtime as a fallback" + depends on UCLIBC_HAS_TZ_FILE + default y + help + Answer Y to try to use /etc/localtime file. + On glibc systems this file (if it is in TZif2 format) + contains timezone string at the end. + + Most people will answer Y. + endmenu menu "Advanced Library Settings" diff --git a/libc/misc/time/time.c b/libc/misc/time/time.c index dfa8c0daf..f80104ee1 100644 --- a/libc/misc/time/time.c +++ b/libc/misc/time/time.c @@ -1804,12 +1804,12 @@ static smallint TZ_file_read; /* Let BSS initialization set this to 0. */ static char *read_TZ_file(char *buf) { + int r; int fd; char *p = NULL; fd = open(__UCLIBC_TZ_FILE_PATH__, O_RDONLY); if (fd >= 0) { - ssize_t r; #if 0 /* TZ are small *files*. On files, short reads * only occur on EOF (unlike, say, pipes). @@ -1829,13 +1829,12 @@ static char *read_TZ_file(char *buf) todo -= r; } while (todo); #else - /* Shorter, and does one less read syscall */ + /* Shorter, and does one fewer read syscall */ r = read(fd, buf, TZ_BUFLEN); if (r < 0) goto ERROR; p = buf + r; #endif - if ((p > buf) && (p[-1] == '\n')) { /* Must end with newline */ p[-1] = 0; p = buf; @@ -1848,6 +1847,45 @@ ERROR: } close(fd); } +#ifdef __UCLIBC_FALLBACK_TO_ETC_LOCALTIME__ + else { + fd = open("/etc/localtime", O_RDONLY); + if (fd >= 0) { + r = read(fd, buf, TZ_BUFLEN); + if (r != TZ_BUFLEN + || strncmp(buf, "TZif", 4) != 0 + || (unsigned char)buf[4] < 2 + || lseek(fd, -TZ_BUFLEN, SEEK_END) < 0 + ) { + goto ERROR; + } + /* tzfile.h from tzcode database says about TZif2+ files: + ** + ** If tzh_version is '2' or greater, the above is followed by a second instance + ** of tzhead and a second instance of the data in which each coded transition + ** time uses 8 rather than 4 chars, + ** then a POSIX-TZ-environment-variable-style string for use in handling + ** instants after the last transition time stored in the file + ** (with nothing between the newlines if there is no POSIX representation for + ** such instants). + */ + r = read(fd, buf, TZ_BUFLEN); + if (r <= 0 || buf[--r] != '\n') + goto ERROR; + buf[r] = 0; + while (r != 0) { + if (buf[--r] == '\n') { + p = buf + r + 1; +#ifndef __UCLIBC_HAS_TZ_FILE_READ_MANY__ + TZ_file_read = 1; +#endif + break; + } + } /* else ('\n' not found): p remains NULL */ + close(fd); + } + } +#endif /* __UCLIBC_FALLBACK_TO_ETC_LOCALTIME__ */ return p; } |