diff options
Diffstat (limited to 'examples/scripts/timeout3')
| -rw-r--r-- | examples/scripts/timeout3 | 83 |
1 files changed, 42 insertions, 41 deletions
diff --git a/examples/scripts/timeout3 b/examples/scripts/timeout3 index 5c19d2e..de650be 100644 --- a/examples/scripts/timeout3 +++ b/examples/scripts/timeout3 @@ -1,56 +1,57 @@ #!/bin/bash # -# The Bash shell script executes a command with a time-out. -# Upon time-out expiration SIGTERM (15) is sent to the process. If the signal +# The Bash script executes a command with a time-out. +# Based on the Bash documentation example. +# +# Upon time-out expiration SIGTERM (15) is sent to the process. If the signal # is blocked, then the subsequent SIGKILL (9) terminates it. +# Dmitry V Golovashkin (E-mail: dvg@ieee.org) # -# Based on the Bash documentation example. +script_name="${0##*/}" -# Hello Chet, -# please find attached a "little easier" :-) to comprehend -# time-out example. If you find it suitable, feel free to include -# anywhere: the very same logic as in the original examples/scripts, a -# little more transparent implementation to my taste. -# -# Dmitry V Golovashkin <Dmitry.Golovashkin@sas.com> +# Default values. +readonly param_timeout=5 +readonly param_interval=1 +readonly param_delay=1 -scriptName="${0##*/}" +declare -i timeout=param_timeout +declare -i interval=param_interval +declare -i delay=param_delay -declare -i DEFAULT_TIMEOUT=9 -declare -i DEFAULT_INTERVAL=1 -declare -i DEFAULT_DELAY=1 +blue="$(tput setaf 4)" +bold_red="$(tput bold; tput setaf 1)" +off="$(tput sgr0)" -# Timeout. -declare -i timeout=DEFAULT_TIMEOUT -# Interval between checks if the process is still alive. -declare -i interval=DEFAULT_INTERVAL -# Delay between posting the SIGTERM signal and destroying the process by SIGKILL. -declare -i delay=DEFAULT_DELAY +function print_usage() { +cat <<EOF -function printUsage() { - cat <<EOF +Synopsis: $script_name [-t timeout] [-i interval] [-d delay] command -Synopsis - $scriptName [-t timeout] [-i interval] [-d delay] command - Execute a command with a time-out. - Upon time-out expiration SIGTERM (15) is sent to the process. If SIGTERM - signal is blocked, then the subsequent SIGKILL (9) terminates it. +Executes the command with a time-out. Upon time-out expiration SIGTERM (15) is +sent to the process. If SIGTERM signal is blocked, then the subsequent SIGKILL +(9) terminates it. - -t timeout - Number of seconds to wait for command completion. - Default value: $DEFAULT_TIMEOUT seconds. +$blue-t timeout$off + Number of seconds to wait for command completion. + Default value: $param_timeout seconds. In some practical situations + this value ${bold_red}must$off be increased (for instance -t 180) to allow + the command to complete. - -i interval - Interval between checks if the process is still alive. - Positive integer, default value: $DEFAULT_INTERVAL seconds. +$blue-i interval$off + Interval between checks if the process is still alive. + Positive integer, default value: $param_interval seconds. + Default value is OK for most situations. - -d delay - Delay between posting the SIGTERM signal and destroying the - process by SIGKILL. Default value: $DEFAULT_DELAY seconds. +$blue-d delay$off + Delay between posting the SIGTERM signal and destroying the process by + SIGKILL. Default value: $param_delay seconds. + Default value is OK for most situations. As of today, Bash does not support floating point arithmetic (sleep does), -therefore all delay/time values must be integers. +therefore all time values must be integers. +Dmitry Golovashkin (E-mail: dvg@ieee.org) EOF +exit 1 # No useful work was done. } # Options. @@ -59,7 +60,7 @@ while getopts ":t:i:d:" option; do t) timeout=$OPTARG ;; i) interval=$OPTARG ;; d) delay=$OPTARG ;; - *) printUsage; exit 1 ;; + *) print_usage ;; esac done shift $((OPTIND - 1)) @@ -67,11 +68,10 @@ shift $((OPTIND - 1)) # $# should be at least 1 (the command to execute), however it may be strictly # greater than 1 if the command itself has options. if (($# == 0 || interval <= 0)); then - printUsage - exit 1 + print_usage fi -# kill -0 pid Exit code indicates if a signal may be sent to $pid process. +# kill -0 pid Exit code indicates if a signal may be sent to "pid" process. ( ((t = timeout)) @@ -89,3 +89,4 @@ fi ) 2> /dev/null & exec "$@" + |