1 /* 2 * Copyright 2002-2013, Axel Dörfler, axeld@pinc-software.de. 3 * Distributed under the terms of the MIT License. 4 */ 5 6 7 #include <errno.h> 8 #include <unistd.h> 9 10 #include <errno_private.h> 11 #include <syscalls.h> 12 #include <syscall_utils.h> 13 14 15 ssize_t 16 readlink(const char *path, char *buffer, size_t bufferSize) 17 { 18 return readlinkat(AT_FDCWD, path, buffer, bufferSize); 19 } 20 21 22 ssize_t 23 readlinkat(int fd, const char *path, char *buffer, size_t bufferSize) 24 { 25 size_t linkLen = bufferSize; 26 status_t status = _kern_read_link(fd, path, buffer, &linkLen); 27 if (status < B_OK) { 28 __set_errno(status); 29 return -1; 30 } 31 32 // If the buffer is big enough, null-terminate the string. That's not 33 // required by the standard, but helps non-conforming apps. 34 if (linkLen < bufferSize) 35 buffer[linkLen] = '\0'; 36 37 // _kern_read_link() returns the length of the link, but readlinkat() is 38 // supposed to return the number of bytes placed into buffer. If the 39 // buffer is larger than the link contents, then linkLen is the number 40 // of bytes written to the buffer. Otherwise, bufferSize bytes will have 41 // been written. 42 return min_c(linkLen, bufferSize); 43 } 44 45 46 int 47 symlink(const char *toPath, const char *symlinkPath) 48 { 49 return symlinkat(toPath, AT_FDCWD, symlinkPath); 50 } 51 52 53 int 54 symlinkat(const char *toPath, int fd, const char *symlinkPath) 55 { 56 RETURN_AND_SET_ERRNO(_kern_create_symlink(fd, symlinkPath, toPath, 0)); 57 } 58 59 60 int 61 unlink(const char *path) 62 { 63 return unlinkat(AT_FDCWD, path, 0); 64 } 65 66 67 int 68 unlinkat(int fd, const char *path, int flag) 69 { 70 if ((flag & AT_REMOVEDIR) != 0) 71 RETURN_AND_SET_ERRNO(_kern_remove_dir(fd, path)); 72 else 73 RETURN_AND_SET_ERRNO(_kern_unlink(fd, path)); 74 } 75 76 77 int 78 link(const char *toPath, const char *linkPath) 79 { 80 return linkat(AT_FDCWD, toPath, AT_FDCWD, linkPath, 0); 81 } 82 83 84 int 85 linkat(int toFD, const char *toPath, int linkFD, const char *linkPath, int flag) 86 { 87 int status = _kern_create_link(linkFD, linkPath, toFD, toPath, 88 (flag & AT_SYMLINK_FOLLOW) != 0); 89 90 // Haiku -> POSIX error mapping 91 if (status == B_UNSUPPORTED) 92 status = EPERM; 93 94 RETURN_AND_SET_ERRNO(status); 95 } 96