diff options
| -rw-r--r-- | usr.bin/sed/main.c | 54 |
1 files changed, 26 insertions, 28 deletions
diff --git a/usr.bin/sed/main.c b/usr.bin/sed/main.c index 8b97486..2ccc988 100644 --- a/usr.bin/sed/main.c +++ b/usr.bin/sed/main.c @@ -413,9 +413,7 @@ inplace_edit(filename) char **filename; { struct stat orig; - int input, output; char backup[MAXPATHLEN]; - char *buffer; if (lstat(*filename, &orig) == -1) err(1, "lstat"); @@ -425,36 +423,36 @@ inplace_edit(filename) } if (*inplace == '\0') { - char template[] = "/tmp/sed.XXXXXXXXXX"; - - output = mkstemp(template); - if (output == -1) - err(1, "mkstemp"); - strlcpy(backup, template, MAXPATHLEN); + /* + * This is a bit of a hack: we use mkstemp() to avoid the + * mktemp() link-time warning, although mktemp() would fit in + * this context much better. We're only interested in getting + * a name for use in the rename(); there aren't any security + * issues here that don't already exist in relation to the + * original file and its directory. + */ + int fd; + strlcpy(backup, *filename, sizeof(backup)); + strlcat(backup, ".XXXXXXXXXX", sizeof(backup)); + fd = mkstemp(backup); + if (fd == -1) + errx(1, "could not create backup of %s", *filename); + else + close(fd); } else { - strlcpy(backup, *filename, MAXPATHLEN); - strlcat(backup, inplace, MAXPATHLEN); - output = open(backup, O_WRONLY | O_CREAT | O_TRUNC); - if (output == -1) - err(1, "open(%s)", backup); + strlcpy(backup, *filename, sizeof(backup)); + strlcat(backup, inplace, sizeof(backup)); } - input = open(*filename, O_RDONLY); - if (input == -1) - err(1, "open(%s)", *filename); - if (fchmod(output, orig.st_mode & ~S_IFMT) == -1) - err(1, "chmod"); - buffer = (char *)mmap(0, orig.st_size, PROT_READ, MAP_SHARED, input, 0); - if (buffer == MAP_FAILED) - err(1, "mmap(%s)", *filename); - if (write(output, buffer, orig.st_size) == -1) - err(1, "write(%s)", backup); - if (munmap(buffer, orig.st_size) == -1) - err(1, "munmap(%s)", *filename); - close(input); - close(output); - freopen(*filename, "w", stdout); + if (rename(*filename, backup) == -1) + err(1, "rename(\"%s\", \"%s\")", *filename, backup); + if (freopen(*filename, "w", stdout) == NULL) + err(1, "open(\"%s\")", *filename); + if (fchmod(fileno(stdout), orig.st_mode) == -1) + err(1, "chmod(\"%s\")", *filename); *filename = strdup(backup); + if (*filename == NULL) + err(1, "malloc"); return 0; } |
