1/* vi: set sw=4 ts=4: */ 2/* 3 * Utility routines. 4 * 5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> 6 * 7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. 8 */ 9#include "libbb.h" 10 11ssize_t FAST_FUNC safe_read(int fd, void *buf, size_t count) 12{ 13 ssize_t n; 14 15 do { 16 n = read(fd, buf, count); 17 } while (n < 0 && errno == EINTR); 18 19 return n; 20} 21 22/* 23 * Read all of the supplied buffer from a file. 24 * This does multiple reads as necessary. 25 * Returns the amount read, or -1 on an error. 26 * A short read is returned on an end of file. 27 */ 28ssize_t FAST_FUNC full_read(int fd, void *buf, size_t len) 29{ 30 ssize_t cc; 31 ssize_t total; 32 33 total = 0; 34 35 while (len) { 36 cc = safe_read(fd, buf, len); 37 38 if (cc < 0) { 39 if (total) { 40 /* we already have some! */ 41 /* user can do another read to know the error code */ 42 return total; 43 } 44 return cc; /* read() returns -1 on failure. */ 45 } 46 if (cc == 0) 47 break; 48 buf = ((char *)buf) + cc; 49 total += cc; 50 len -= cc; 51 } 52 53 return total; 54} 55 56ssize_t FAST_FUNC read_close(int fd, void *buf, size_t size) 57{ 58 /*int e;*/ 59 size = full_read(fd, buf, size); 60 /*e = errno;*/ 61 close(fd); 62 /*errno = e;*/ 63 return size; 64} 65 66ssize_t FAST_FUNC open_read_close(const char *filename, void *buf, size_t size) 67{ 68 int fd = open(filename, O_RDONLY); 69 if (fd < 0) 70 return fd; 71 return read_close(fd, buf, size); 72} 73