如何将shell脚本转换为一行并通过Python子进程执行?

2 投票
1 回答
1388 浏览
提问于 2025-04-17 22:14

我有一个简单的shell脚本,想把它转换成一行,这样我就可以通过我的Python程序来执行它,使用的是subprocess模块。

#!/bin/bash
set -e

COUNT=60   #number of 10 second timeouts in 10 minutes
SUM_SYNCS=0
SUM_SYNCS_BEHIND=0
HOSTNAME=$hostname

echo $HOSTNAME

while [[ $COUNT -ge "0" ]]; do

#send the request, put response in variable
DATA=$(wget -O - -q -t 1 http://$HOSTNAME:8080/beat)

#grep $DATA for syncs and syncs_behind
SYNCS=$(echo $DATA | grep -oE 'num_syncs: [0-9]+' | awk '{print $2}')
SYNCS_BEHIND=$(echo $DATA | grep -oE 'num_syncs_behind: [0-9]+' | awk '{print $2}')

echo $SYNCS
echo $SYNCS_BEHIND

#verify conditionals
if [[ $SYNCS -gt "8" && $SYNCS_BEHIND -eq "0" ]]; then exit 0; fi

#decrement the counter
let COUNT-=1

#wait another 10 seconds
sleep 10

done

我把上面的脚本转换成了一行,像这样:

jsonStr = {"script": "#!/bin/bash\nset -e\n\nCOUNT=60   #number of 10 second timeouts in 10 minutes\nSUM_SYNCS=0\nSUM_SYNCS_BEHIND=0\nHOSTNAME=$hostname\t\n\necho $HOSTNAME\n\nwhile [[ $COUNT -ge \"0\" ]]; do\n\n#send the request, put response in variable\nDATA=$(wget -O - -q -t 1 http://$HOSTNAME:8080/beat)\n\n#grep $DATA for syncs and syncs_behind\nSYNCS=$(echo $DATA | grep -oE 'num_syncs: [0-9]+' | awk '{print $2}')\nSYNCS_BEHIND=$(echo $DATA | grep -oE 'num_syncs_behind: [0-9]+' | awk '{print $2}')\n\necho $SYNCS\necho $SYNCS_BEHIND\n\n#verify conditionals\nif [[ $SYNCS -gt \"8\" && $SYNCS_BEHIND -eq \"0\" ]]; then exit 0; fi\n\n#decrement the counter\nlet COUNT-=1\n\n#wait another 10 seconds\nsleep 10\n\ndone\n"}

然后我尝试用Python的subprocess来执行这个一行的脚本,但每次都会出错。

  File "C:\Python27\lib\json\__init__.py", line 326, in loads
    return _default_decoder.decode(s)
  File "C:\Python27\lib\json\decoder.py", line 366, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
TypeError: expected string or buffer

下面是我正在尝试的完整Python代码:

jsonStr = {"script": "#!/bin/bash\nset -e\n\nCOUNT=60   #number of 10 second timeouts in 10 minutes\nSUM_SYNCS=0\nSUM_SYNCS_BEHIND=0\nHOSTNAME=$hostname\t#\n\necho $HOSTNAME\n\nwhile [[ $COUNT -ge \"0\" ]]; do\n\n#send the request, put response in variable\nDATA=$(wget -O - -q -t 1 http://$HOSTNAME:8080/beat)\n\n#grep $DATA for syncs and syncs_behind\nSYNCS=$(echo $DATA | grep -oE 'num_syncs: [0-9]+' | awk '{print $2}')\nSYNCS_BEHIND=$(echo $DATA | grep -oE 'num_syncs_behind: [0-9]+' | awk '{print $2}')\n\necho $SYNCS\necho $SYNCS_BEHIND\n\n#verify conditionals\nif [[ $SYNCS -gt \"8\" && $SYNCS_BEHIND -eq \"0\" ]]; then exit 0; fi\n\n#decrement the counter\nlet COUNT-=1\n\n#wait another 10 seconds\nsleep 10\n\ndone\n"}

j = json.loads(jsonStr)

print "start"
proc = subprocess.Popen(j['script'], shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, executable='/bin/bash')
(stdout, stderr) = proc.communicate()
print stdout
print stderr
print "end" 

我把shell脚本转换成一行后,哪里出了问题呢?有什么想法吗?

注意:我其他的shell脚本都是一行的,并且可以正常工作,只有这个脚本出现了一些问题。

1 个回答

2

你遇到的错误是因为 json.loads(jsonStr) 这行代码。json.loads 需要一个 str(字符串)或者 unicode(一种特殊的字符串格式),而不是 dict(字典)。而 jsonStr 已经是一个 dict 了,所以你不需要再用 json.loads 来处理它。

撰写回答