限制shell腳本執行的次數

Question

如何限制shell腳本執行的次數。我試過shc，但只有時間限制而沒有使用限制。

Answer 1

您可以使用一個文件作爲「運行計數器」並在執行過程中讀取該文件，以查看腳本以前運行過多少次。

如果您希望「numOfRuns.txt」文件在重新啓動後保留，請使用與/ tmp不同的目錄作爲根目錄。

這是一個limitedScript.sh，演示了這一點，首先沒有評論，然後用。

#!/bin/bash 

runCountFile="/tmp/numOfRuns.txt" 
maxRuns=3 

if [ -e "$runCountFile" ]; then 
    read value < "$runCountFile" 
else 
    value=0 
fi 

if ((value >= maxRuns)); then 
    echo "Script has been run too many times" 
    exit 
else 
    newValue=$((value + 1)) 
    echo $newValue > "$runCountFile" 
fi 

-

#!/bin/bash 

# limitedScript.sh: Demonstrates simple run-limiting through a file-based counter 

runCountFile="/tmp/numOfRuns.txt" # the file to store the number of times the script has run 
maxRuns=3 # maximum number of executions for this script 

if [ -e "$runCountFile" ]; then # does the run counter file exist? 
    value=`cat $runCountFile` # read the value from the file 
else 
    value=0 # the script has never run yet if the "run counter" file doesn't exist 
fi 

if ((value >= maxRuns)); then 
    echo "Script has been run too many times" 
    exit 
else 
    newValue=$((value + 1)) 
    echo $newValue > "$runCountFile" #update the "run counter" file 
fi 

OUTPUT：

root@dev:/tmp# rm numOfRuns.txt 
root@dev:/tmp# ./limitedScript.sh 
root@dev:/tmp# ./limitedScript.sh 
root@dev:/tmp# ./limitedScript.sh 
root@dev:/tmp# ./limitedScript.sh 
Script has been run too many times