From 19ced5c4253bc154aa499a72b6343e01245c92c0 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sun, 6 Jun 2010 21:53:09 +0200 Subject: pipe_progress: make it independent of printf machinery function old new delta bb_putchar_stderr - 24 +24 ParseField 494 471 -23 progress_meter 212 188 -24 xargs_main 888 842 -46 pipe_progress_main 151 105 -46 ------------------------------------------------------------------------------ (add/remove: 2/0 grow/shrink: 0/4 up/down: 24/-139) Total: -115 bytes Signed-off-by: Denys Vlasenko --- libbb/read_printf.c | 374 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 374 insertions(+) create mode 100644 libbb/read_printf.c (limited to 'libbb/read_printf.c') diff --git a/libbb/read_printf.c b/libbb/read_printf.c new file mode 100644 index 000000000..53f528f5a --- /dev/null +++ b/libbb/read_printf.c @@ -0,0 +1,374 @@ +/* vi: set sw=4 ts=4: */ +/* + * Utility routines. + * + * Copyright (C) 1999-2004 by Erik Andersen + * + * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. + */ +#include "libbb.h" + +#define ZIPPED (ENABLE_FEATURE_SEAMLESS_LZMA \ + || ENABLE_FEATURE_SEAMLESS_BZ2 \ + || ENABLE_FEATURE_SEAMLESS_GZ \ + /* || ENABLE_FEATURE_SEAMLESS_Z */ \ +) + +#if ZIPPED +# include "unarchive.h" +#endif + + +/* Suppose that you are a shell. You start child processes. + * They work and eventually exit. You want to get user input. + * You read stdin. But what happens if last child switched + * its stdin into O_NONBLOCK mode? + * + * *** SURPRISE! It will affect the parent too! *** + * *** BIG SURPRISE! It stays even after child exits! *** + * + * This is a design bug in UNIX API. + * fcntl(0, F_SETFL, fcntl(0, F_GETFL) | O_NONBLOCK); + * will set nonblocking mode not only on _your_ stdin, but + * also on stdin of your parent, etc. + * + * In general, + * fd2 = dup(fd1); + * fcntl(fd2, F_SETFL, fcntl(fd2, F_GETFL) | O_NONBLOCK); + * sets both fd1 and fd2 to O_NONBLOCK. This includes cases + * where duping is done implicitly by fork() etc. + * + * We need + * fcntl(fd2, F_SETFD, fcntl(fd2, F_GETFD) | O_NONBLOCK); + * (note SETFD, not SETFL!) but such thing doesn't exist. + * + * Alternatively, we need nonblocking_read(fd, ...) which doesn't + * require O_NONBLOCK dance at all. Actually, it exists: + * n = recv(fd, buf, len, MSG_DONTWAIT); + * "MSG_DONTWAIT: + * Enables non-blocking operation; if the operation + * would block, EAGAIN is returned." + * but recv() works only for sockets! + * + * So far I don't see any good solution, I can only propose + * that affected readers should be careful and use this routine, + * which detects EAGAIN and uses poll() to wait on the fd. + * Thankfully, poll() doesn't care about O_NONBLOCK flag. + */ +ssize_t FAST_FUNC nonblock_safe_read(int fd, void *buf, size_t count) +{ + struct pollfd pfd[1]; + ssize_t n; + + while (1) { + n = safe_read(fd, buf, count); + if (n >= 0 || errno != EAGAIN) + return n; + /* fd is in O_NONBLOCK mode. Wait using poll and repeat */ + pfd[0].fd = fd; + pfd[0].events = POLLIN; + safe_poll(pfd, 1, -1); /* note: this pulls in printf */ + } +} + +// Reads one line a-la fgets (but doesn't save terminating '\n'). +// Reads byte-by-byte. Useful when it is important to not read ahead. +// Bytes are appended to pfx (which must be malloced, or NULL). +char* FAST_FUNC xmalloc_reads(int fd, char *buf, size_t *maxsz_p) +{ + char *p; + size_t sz = buf ? strlen(buf) : 0; + size_t maxsz = maxsz_p ? *maxsz_p : (INT_MAX - 4095); + + goto jump_in; + while (sz < maxsz) { + if ((size_t)(p - buf) == sz) { + jump_in: + buf = xrealloc(buf, sz + 128); + p = buf + sz; + sz += 128; + } + /* nonblock_safe_read() because we are used by e.g. shells */ + if (nonblock_safe_read(fd, p, 1) != 1) { /* EOF/error */ + if (p == buf) { /* we read nothing */ + free(buf); + return NULL; + } + break; + } + if (*p == '\n') + break; + p++; + } + *p = '\0'; + if (maxsz_p) + *maxsz_p = p - buf; + p++; + return xrealloc(buf, p - buf); +} + +// Read (potentially big) files in one go. File size is estimated +// by stat. Extra '\0' byte is appended. +void* FAST_FUNC xmalloc_read(int fd, size_t *maxsz_p) +{ + char *buf; + size_t size, rd_size, total; + size_t to_read; + struct stat st; + + to_read = maxsz_p ? *maxsz_p : (INT_MAX - 4095); /* max to read */ + + /* Estimate file size */ + st.st_size = 0; /* in case fstat fails, assume 0 */ + fstat(fd, &st); + /* /proc/N/stat files report st_size 0 */ + /* In order to make such files readable, we add small const */ + size = (st.st_size | 0x3ff) + 1; + + total = 0; + buf = NULL; + while (1) { + if (to_read < size) + size = to_read; + buf = xrealloc(buf, total + size + 1); + rd_size = full_read(fd, buf + total, size); + if ((ssize_t)rd_size == (ssize_t)(-1)) { /* error */ + free(buf); + return NULL; + } + total += rd_size; + if (rd_size < size) /* EOF */ + break; + if (to_read <= rd_size) + break; + to_read -= rd_size; + /* grow by 1/8, but in [1k..64k] bounds */ + size = ((total / 8) | 0x3ff) + 1; + if (size > 64*1024) + size = 64*1024; + } + buf = xrealloc(buf, total + 1); + buf[total] = '\0'; + + if (maxsz_p) + *maxsz_p = total; + return buf; +} + +#ifdef USING_LSEEK_TO_GET_SIZE +/* Alternatively, file size can be obtained by lseek to the end. + * The code is slightly bigger. Retained in case fstat approach + * will not work for some weird cases (/proc, block devices, etc). + * (NB: lseek also can fail to work for some weird files) */ + +// Read (potentially big) files in one go. File size is estimated by +// lseek to end. +void* FAST_FUNC xmalloc_open_read_close(const char *filename, size_t *maxsz_p) +{ + char *buf; + size_t size; + int fd; + off_t len; + + fd = open(filename, O_RDONLY); + if (fd < 0) + return NULL; + + /* /proc/N/stat files report len 0 here */ + /* In order to make such files readable, we add small const */ + size = 0x3ff; /* read only 1k on unseekable files */ + len = lseek(fd, 0, SEEK_END) | 0x3ff; /* + up to 1k */ + if (len != (off_t)-1) { + xlseek(fd, 0, SEEK_SET); + size = maxsz_p ? *maxsz_p : (INT_MAX - 4095); + if (len < size) + size = len; + } + + buf = xmalloc(size + 1); + size = read_close(fd, buf, size); + if ((ssize_t)size < 0) { + free(buf); + return NULL; + } + buf = xrealloc(buf, size + 1); + buf[size] = '\0'; + + if (maxsz_p) + *maxsz_p = size; + return buf; +} +#endif + +// Read (potentially big) files in one go. File size is estimated +// by stat. +void* FAST_FUNC xmalloc_open_read_close(const char *filename, size_t *maxsz_p) +{ + char *buf; + int fd; + + fd = open(filename, O_RDONLY); + if (fd < 0) + return NULL; + + buf = xmalloc_read(fd, maxsz_p); + close(fd); + return buf; +} + +/* Die with an error message if we can't read the entire buffer. */ +void FAST_FUNC xread(int fd, void *buf, size_t count) +{ + if (count) { + ssize_t size = full_read(fd, buf, count); + if ((size_t)size != count) + bb_error_msg_and_die("short read"); + } +} + +/* Die with an error message if we can't read one character. */ +unsigned char FAST_FUNC xread_char(int fd) +{ + char tmp; + xread(fd, &tmp, 1); + return tmp; +} + +void* FAST_FUNC xmalloc_xopen_read_close(const char *filename, size_t *maxsz_p) +{ + void *buf = xmalloc_open_read_close(filename, maxsz_p); + if (!buf) + bb_perror_msg_and_die("can't read '%s'", filename); + return buf; +} + +/* Used by e.g. rpm which gives us a fd without filename, + * thus we can't guess the format from filename's extension. + */ +#if ZIPPED +void FAST_FUNC setup_unzip_on_fd(int fd /*, int fail_if_not_detected*/) +{ + const int fail_if_not_detected = 1; + union { + uint8_t b[4]; + uint16_t b16[2]; + uint32_t b32[1]; + } magic; + int offset = -2; +# if BB_MMU + IF_DESKTOP(long long) int FAST_FUNC (*xformer)(int src_fd, int dst_fd); + enum { xformer_prog = 0 }; +# else + enum { xformer = 0 }; + const char *xformer_prog; +# endif + + /* .gz and .bz2 both have 2-byte signature, and their + * unpack_XXX_stream wants this header skipped. */ + xread(fd, magic.b16, sizeof(magic.b16)); + if (ENABLE_FEATURE_SEAMLESS_GZ + && magic.b16[0] == GZIP_MAGIC + ) { +# if BB_MMU + xformer = unpack_gz_stream; +# else + xformer_prog = "gunzip"; +# endif + goto found_magic; + } + if (ENABLE_FEATURE_SEAMLESS_BZ2 + && magic.b16[0] == BZIP2_MAGIC + ) { +# if BB_MMU + xformer = unpack_bz2_stream; +# else + xformer_prog = "bunzip2"; +# endif + goto found_magic; + } + if (ENABLE_FEATURE_SEAMLESS_XZ + && magic.b16[0] == XZ_MAGIC1 + ) { + /* .xz signature: 0xfd, '7', 'z', 'X', 'Z', 0x00 */ + /* More info at: http://tukaani.org/xz/xz-file-format.txt */ + offset = -6; + xread(fd, magic.b32, sizeof(magic.b32)); + if (magic.b32[0] == XZ_MAGIC2) { +# if BB_MMU + xformer = unpack_xz_stream; + /* unpack_xz_stream wants fd at position 0 */ + xlseek(fd, offset, SEEK_CUR); +# else + xformer_prog = "unxz"; +# endif + goto found_magic; + } + } + + /* No known magic seen */ + if (fail_if_not_detected) + bb_error_msg_and_die("no gzip" + IF_FEATURE_SEAMLESS_BZ2("/bzip2") + IF_FEATURE_SEAMLESS_XZ("/xz") + " magic"); + xlseek(fd, offset, SEEK_CUR); + return; + + found_magic: +# if !BB_MMU + /* NOMMU version of open_transformer execs + * an external unzipper that wants + * file position at the start of the file */ + xlseek(fd, offset, SEEK_CUR); +# endif + open_transformer(fd, xformer, xformer_prog); +} +#endif /* ZIPPED */ + +int FAST_FUNC open_zipped(const char *fname) +{ +#if !ZIPPED + return open(fname, O_RDONLY); +#else + char *sfx; + int fd; + + fd = open(fname, O_RDONLY); + if (fd < 0) + return fd; + + sfx = strrchr(fname, '.'); + if (sfx) { + sfx++; + if (ENABLE_FEATURE_SEAMLESS_LZMA && strcmp(sfx, "lzma") == 0) + /* .lzma has no header/signature, just trust it */ + open_transformer(fd, unpack_lzma_stream, "unlzma"); + else + if ((ENABLE_FEATURE_SEAMLESS_GZ && strcmp(sfx, "gz") == 0) + || (ENABLE_FEATURE_SEAMLESS_BZ2 && strcmp(sfx, "bz2") == 0) + || (ENABLE_FEATURE_SEAMLESS_XZ && strcmp(sfx, "xz") == 0) + ) { + setup_unzip_on_fd(fd /*, fail_if_not_detected: 1*/); + } + } + + return fd; +#endif +} + +void* FAST_FUNC xmalloc_open_zipped_read_close(const char *fname, size_t *maxsz_p) +{ + int fd; + char *image; + + fd = open_zipped(fname); + if (fd < 0) + return NULL; + + image = xmalloc_read(fd, maxsz_p); + if (!image) + bb_perror_msg("read error from '%s'", fname); + close(fd); + + return image; +} -- cgit v1.2.3