1 /* mktemp.c - Create a temporary file or directory.
2 *
3 * Copyright 2012 Elie De Brauwer <eliedebrauwer@gmail.com>
4 *
5 * http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/mktemp.html
6
7 USE_MKTEMP(NEWTOY(mktemp, ">1uqd(directory)p(tmpdir):t", TOYFLAG_BIN))
8
9 config MKTEMP
10 bool "mktemp"
11 default y
12 help
13 usage: mktemp [-dqu] [-p DIR] [TEMPLATE]
14
15 Safely create a new file "DIR/TEMPLATE" and print its name.
16
17 -d Create directory instead of file (--directory)
18 -p Put new file in DIR (--tmpdir)
19 -q Quiet, no error messages
20 -t Prefer $TMPDIR > DIR > /tmp (default DIR > $TMPDIR > /tmp)
21 -u Don't create anything, just print what would be created
22
23 Each X in TEMPLATE is replaced with a random printable character. The
24 default TEMPLATE is tmp.XXXXXXXXXX.
25 */
26
27 #define FOR_mktemp
28 #include "toys.h"
29
GLOBALS(char * p;)30 GLOBALS(
31 char *p;
32 )
33
34 void mktemp_main(void)
35 {
36 char *template = *toys.optargs, *dir = TT.p, *te = getenv("TMPDIR");
37 int len;
38
39 // if template, no prefix unless -pt. if !template, always prefix
40 if (!dir || !*dir || (FLAG(t) && te && *te)) dir = te;
41 if (!dir || !*dir) dir = "/tmp";
42 if (!template) template = "tmp.XXXXXXXXXX";
43 else {
44 if (*template == '/' && TT.p && *TT.p) perror_exit("-p + /template");
45 if (!FLAG(p)&&!FLAG(t)) dir = 0;
46 }
47
48 // TODO: coreutils cleans paths, so -p /t/// would result in /t/xxx...
49 template = dir ? xmprintf("%s/%s", dir, template) : xstrdup(template);
50 len = strlen(template);
51 if (len<3 || strcmp(template+len-3, "XXX")) perror_exit("need XXX");
52
53 // In theory you just xputs(mktemp(template)) for -u, in practice there's
54 // link-time deprecation warnings if you do that. So we fake up our own:
55 if (toys.optflags & FLAG_u) {
56 long long rr;
57 char *s = template+len;
58
59 // Fall back to random-ish if xgetrandom fails.
60 if (!xgetrandom(&rr, sizeof(rr), WARN_ONLY)) {
61 struct timespec ts;
62
63 clock_gettime(CLOCK_REALTIME, &ts);
64 rr = ts.tv_nsec*65537+(long)template+getpid()+(long)&template;
65 }
66 // Replace X with 64 chars from posix portable character set (all but "_").
67 while (--s>template) {
68 if (*s != 'X') break;
69 *s = '-'+(rr&63);
70 if (*s>'.') ++*s;
71 if (*s>'9') (*s) += 7;
72 if (*s>'Z') (*s) += 6;
73 rr>>=6;
74 }
75 } else if ((toys.optflags & FLAG_d) ? !mkdtemp(template) : mkstemp(template) == -1) {
76 if (toys.optflags & FLAG_q) {
77 toys.exitval = 1;
78 return;
79 } else perror_exit("Failed to create %s %s/%s",
80 (toys.optflags & FLAG_d) ? "directory" : "file", TT.p, template);
81 }
82
83 xputs(template);
84 if (CFG_TOYBOX_FREE) free(template);
85 }
86