1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
#!/bin/sh
# Create a temporary directory, much like mktemp -d does.
# Copyright (C) 2007-2010 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
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# Written by Jim Meyering.
# Usage: mktempd /tmp phoey.XXXXXXXXXX
# First, try to use the mktemp program.
# Failing that, we'll roll our own mktemp-like function:
# - try to get random bytes from /dev/urandom
# - failing that, generate output from a combination of quickly-varying
# sources and gzip. Ignore non-varying gzip header, and extract
# "random" bits from there.
# - given those bits, map to file-name bytes using tr, and try to create
# the desired directory.
# - make only $MAX_TRIES attempts
ME=`basename "$0"`
die() { echo >&2 "$ME: $@"; exit 1; }
MAX_TRIES=4
rand_bytes()
{
n=$1
chars=abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789
dev_rand=/dev/urandom
if test -r "$dev_rand"; then
# Note: 256-length($chars) == 194; 3 copies of $chars is 186 + 8 = 194.
dd ibs=$n count=1 if="$dev_rand" | tr -c $chars 01234567$chars$chars$chars
return
fi
cmds='date; date +%N; free; who -a; w; ps auxww; ps ef; netstat -n'
data=` (eval "$cmds") 2>&1 | gzip `
n_plus_50=`expr $n + 50`
# Ensure that $data has length at least 50+$n
while :; do
len=`echo "$data"|wc -c`
test $n_plus_50 -le $len && break;
data=` (echo "$data"; eval "$cmds") 2>&1 | gzip `
done
echo "$data" \
| dd bs=1 skip=50 count=$n 2>/dev/null \
| tr -c $chars 01234567$chars$chars$chars
}
mktempd()
{
case $# in
2);;
*) die "Usage: $ME DIR TEMPLATE";;
esac
destdir=$1
template=$2
# Disallow any trailing slash on specified destdir:
# it would subvert the post-mktemp "case"-based destdir test.
case $destdir in
/) ;;
*/) die "invalid destination dir: remove trailing slash(es)";;
esac
case $template in
*XXXX) ;;
*) die "invalid template: $template (must have a suffix of at least 4 X's)";;
esac
fail=0
# First, try to use mktemp.
d=`env -u TMPDIR mktemp -d -t -p "$destdir" "$template" 2>/dev/null` \
|| fail=1
# The resulting name must be in the specified directory.
case $d in "$destdir"*);; *) fail=1;; esac
# It must have created the directory.
test -d "$d" || fail=1
# It must have 0700 permissions. Handle sticky "S" bits.
perms=`ls -dgo "$d" 2>/dev/null|tr S -` || fail=1
case $perms in drwx------*) ;; *) fail=1;; esac
test $fail = 0 && {
echo "$d"
return
}
# If we reach this point, we'll have to create a directory manually.
# Get a copy of the template without its suffix of X's.
base_template=`echo "$template"|sed 's/XX*$//'`
# Calculate how many X's we've just removed.
template_length=`echo "$template" | wc -c`
nx=`echo "$base_template" | wc -c`
nx=`expr $template_length - $nx`
err=
i=1
while :; do
X=`rand_bytes $nx`
candidate_dir="$destdir/$base_template$X"
err=`mkdir -m 0700 "$candidate_dir" 2>&1` \
&& { echo "$candidate_dir"; return; }
test $MAX_TRIES -le $i && break;
i=`expr $i + 1`
done
die "$err"
}
mktempd "$@"
|
