diff options
Diffstat (limited to 'lib/tempname.c')
| -rw-r--r-- | lib/tempname.c | 135 |
1 files changed, 78 insertions, 57 deletions
diff --git a/lib/tempname.c b/lib/tempname.c index 183dae8c..1920274c 100644 --- a/lib/tempname.c +++ b/lib/tempname.c @@ -1,6 +1,6 @@ /* tempname.c - generate the name of a temporary file. - Copyright (C) 1991-2003, 2005-2007, 2009-2014 Free Software Foundation, Inc. + Copyright (C) 1991-2003, 2005-2007, 2009-2015 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -64,6 +64,7 @@ # define struct_stat64 struct stat64 #else # define struct_stat64 struct stat +# define __try_tempname try_tempname # define __gen_tempname gen_tempname # define __getpid getpid # define __gettimeofday gettimeofday @@ -184,30 +185,15 @@ check_x_suffix (char const *s, size_t len) static const char letters[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; -/* Generate a temporary file name based on TMPL. TMPL must match the - rules for mk[s]temp (i.e. end in at least X_SUFFIX_LEN "X"s, - possibly with a suffix). - The name constructed does not exist at the time of the call to - this function. TMPL is overwritten with the result. - - KIND may be one of: - __GT_NOCREATE: simply verify that the name does not exist - at the time of the call. - __GT_FILE: create the file using open(O_CREAT|O_EXCL) - and return a read-write fd. The file is mode 0600. - __GT_DIR: create a directory, which will be mode 0700. - - We use a clever algorithm to get hard-to-predict names. */ int -gen_tempname_len (char *tmpl, int suffixlen, int flags, int kind, - size_t x_suffix_len) +try_tempname_len (char *tmpl, int suffixlen, void *args, + int (*tryfunc) (char *, void *), size_t x_suffix_len) { size_t len; char *XXXXXX; unsigned int count; int fd = -1; int save_errno = errno; - struct_stat64 st; struct randint_source *rand_src; /* A lower bound on the number of temporary files to attempt to @@ -251,45 +237,7 @@ gen_tempname_len (char *tmpl, int suffixlen, int flags, int kind, for (i = 0; i < x_suffix_len; i++) XXXXXX[i] = letters[randint_genmax (rand_src, sizeof letters - 2)]; - switch (kind) - { - case __GT_FILE: - fd = __open (tmpl, - (flags & ~O_ACCMODE) - | O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR); - break; - - case __GT_DIR: - fd = __mkdir (tmpl, S_IRUSR | S_IWUSR | S_IXUSR); - break; - - case __GT_NOCREATE: - /* This case is backward from the other three. This function - succeeds if __xstat fails because the name does not exist. - Note the continue to bypass the common logic at the bottom - of the loop. */ - if (__lxstat64 (_STAT_VER, tmpl, &st) < 0) - { - if (errno == ENOENT) - { - __set_errno (save_errno); - fd = 0; - goto done; - } - else - { - /* Give up now. */ - fd = -1; - goto done; - } - } - continue; - - default: - assert (! "invalid KIND in __gen_tempname"); - abort (); - } - + fd = tryfunc (tmpl, args); if (fd >= 0) { __set_errno (save_errno); @@ -317,8 +265,81 @@ gen_tempname_len (char *tmpl, int suffixlen, int flags, int kind, return fd; } +static int +try_file (char *tmpl, void *flags) +{ + int *openflags = flags; + return __open (tmpl, + (*openflags & ~O_ACCMODE) + | O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR); +} + +static int +try_dir (char *tmpl, void *flags _GL_UNUSED) +{ + return __mkdir (tmpl, S_IRUSR | S_IWUSR | S_IXUSR); +} + +static int +try_nocreate (char *tmpl, void *flags _GL_UNUSED) +{ + struct_stat64 st; + + if (__lxstat64 (_STAT_VER, tmpl, &st) == 0) + __set_errno (EEXIST); + return errno == ENOENT ? 0 : -1; +} + +/* Generate a temporary file name based on TMPL. TMPL must match the + rules for mk[s]temp (i.e., end in at least X_SUFFIX_LEN "X"s, + possibly with a suffix). + The name constructed does not exist at the time of the call to + this function. TMPL is overwritten with the result. + + KIND may be one of: + __GT_NOCREATE: simply verify that the name does not exist + at the time of the call. + __GT_FILE: create the file using open(O_CREAT|O_EXCL) + and return a read-write fd. The file is mode 0600. + __GT_DIR: create a directory, which will be mode 0700. + + We use a clever algorithm to get hard-to-predict names. */ +int +gen_tempname_len (char *tmpl, int suffixlen, int flags, int kind, + size_t x_suffix_len) +{ + int (*tryfunc) (char *, void *); + + switch (kind) + { + case __GT_FILE: + tryfunc = try_file; + break; + + case __GT_DIR: + tryfunc = try_dir; + break; + + case __GT_NOCREATE: + tryfunc = try_nocreate; + break; + + default: + assert (! "invalid KIND in __gen_tempname"); + abort (); + } + return try_tempname_len (tmpl, suffixlen, &flags, tryfunc, x_suffix_len); +} + int __gen_tempname (char *tmpl, int suffixlen, int flags, int kind) { return gen_tempname_len (tmpl, suffixlen, flags, kind, 6); } + +int +__try_tempname (char *tmpl, int suffixlen, void *args, + int (*tryfunc) (char *, void *)) +{ + return try_tempname_len (tmpl, suffixlen, args, tryfunc, 6); +} |