blob: 7d6d57a80f9617af28809b058e16456e35a43050 (
plain) (
blame)
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
|
#!/bin/sh
# Attempt a certain number of times to perform a task, buffer stderr unless and
# until all command attempts fail
self=try
# Parse options
while getopts 's:n:' opt ; do
case $opt in
n)
attn=$OPTARG
;;
s)
sleep=$OPTARG
;;
\?)
printf >&2 '%s: Unknown option\n' "$self"
exit 2
;;
esac
done
shift "$((OPTIND-1))"
# Check we have at least one argument left (the command to run)
if [ "$#" -eq 0 ] ; then
printf >&2 '%s: Need a command to run\n' "$self"
exit 2
fi
# Create a temporary directory with name in $td, and handle POSIX-ish traps to
# remove it when the script exits.
td=
cleanup() {
[ -n "$td" ] && rm -fr -- "$td"
if [ "$1" != EXIT ] ; then
trap - "$1"
kill "-$1" "$$"
fi
}
for sig in EXIT HUP INT TERM ; do
# shellcheck disable=SC2064
trap "cleanup $sig" "$sig"
done
td=$(mktd "$self") || exit
# Open a filehandle to the error buffer, just to save on file operations
errbuff=$td/errbuff
exec 3>"$errbuff"
# Keep trying the command, writing error output to the buffer file, and exit
# if we succeed on any of them
attc=1
: "${attn:=3}" "${sleep:=0}"
while [ "$attc" -le "$attn" ] ; do
# Try running the command; if it succeeds, we're done, and any previous
# failures get their errors discarded
if "$@" 2>&3 ; then
exit
# If the command failed, record the exit value
else
ex=$?
fi
# If this isn't the last run, have a sleep
if [ "$attc" -lt "$attn" ] ; then
sleep "${sleep:=0}"
fi
# Increment the attempt count
attc=$((attc + 1))
done
# Attempts were exhausted, and all failed; print the error output from all of
# the failures and exit with the non-zero exit value of the most recent one
exec 3>&-
cat -- "$td"/errbuff >&2
exit "$ex"
|