使用sudo python腳本的crontab

Question

好的，我找到了一些東西。不知道如何解決它。我已經看到這是谷歌出現的一個常見錯誤。這個錯誤似乎與環境變量或某事有關。不知道如何處理這個問題：

這是代碼，它也正是子被稱爲導致錯誤的部分：

#!/usr/bin/python 

import subprocess 
import re 
import sys 
import time 
import datetime 
import gspread 

# =========================================================================== 
# Google Account Details 
# =========================================================================== 

# Account details for google docs 
email  = 'my_email@gmail.com' 
password = 'my_password' 
spreadsheet = 'my_spreadsheet' 

# =========================================================================== 
# Example Code 
# =========================================================================== 


# Login with your Google account 
try: 
    gc = gspread.login(email, password) 
except: 
    print "Unable to log in. Check your email address/password" 
    sys.exit() 

# Open a worksheet from your spreadsheet using the filename 
try: 
    worksheet = gc.open(spreadsheet).sheet1 
    # Alternatively, open a spreadsheet using the spreadsheet's key 
    # worksheet = gc.open_by_key('0BmgG6nO_6dprdS1MN3d3MkdPa142WFRrdnRRUWl1UFE') 
except: 
    print "Unable to open the spreadsheet. Check your filename: %s" % spreadsheet 
    sys.exit() 

# Continuously append data 
while(True): 
    # Run the DHT program to get the humidity and temperature readings! 

    output = subprocess.check_output(["./Adafruit_DHT", "2302", "17"]); 
    print output 
    matches = re.search("Temp =\s+([0-9.]+)", output) 
    if (not matches): 
     time.sleep(3) 
     continue 
    temp1 = float(matches.group(1)) 
    temp = temp1*9/5+32 # added the extra step to converto to fahrenheit 

    # search for humidity printout 
    matches = re.search("Hum =\s+([0-9.]+)", output) 
    if (not matches): 
     time.sleep(3) 
     continue 
    humidity = float(matches.group(1)) 

    print "Temperature: %.1f F" % temp 
    print "Humidity: %.1f %%" % humidity 

    # Append the data in the spreadsheet, including a timestamp 
    try: 
    values = [datetime.datetime.now(), temp, humidity] 
    worksheet.append_row(values) 
    except: 
    print "Unable to append data. Check your connection?" 
    sys.exit() 

    # Wait 30 seconds before continuing or just exit 
    print "Wrote a row to %s" % spreadsheet 
# time.sleep(60) 
    sys.exit() 

這基本上它。只要Adafruit_DHT程序在同一個目錄中，它就可以正常使用'sudo python script.py'。

這是我得到的錯誤：

Traceback (most recent call last): 
    File "/home/pi/Adafruit/dht/Ada_temp.py", line 44, in <module> 
    output = subprocess.check_output(["./home/pi/Adafruit/dht/Adafruit_DHT", "2302", "17"]); 
    File "/usr/lib/python2.7/subprocess.py", line 537, in check_output 
    process = Popen(stdout=PIPE, *popenargs, **kwargs) 
    File "/usr/lib/python2.7/subprocess.py", line 679, in __init__ 
    errread, errwrite) 
    File "/usr/lib/python2.7/subprocess.py", line 1259, in _execute_child 
    raise child_exception 
OSError: [Errno 2] No such file or directory 

我已經嘗試添加C程序（Adafruit_DHT）的完整路徑，都無濟於事......

Answer 1

找到問題。

1. 腳本是否可以運行？ 在腳本的第一行做一些小事，看它實際上是從cron（例如：寫入/ tmp中的文件）執行的。

2. 一旦你設法運行它，尋找其他問題。 Cron可以設置爲發送帶有腳本輸出的郵件。我看到的一件顯而易見的事情是：./Adafruit_DHT，使用相對路徑，這是一個不好的跡象，cron腳本可能不會在您認爲它執行的目錄中執行。修復它（=使用絕對路徑）。

Answer 2

嘗試：

output = subprocess.check_output(["PATH_TO_Adafruit_DHT/Adafruit_DHT", "2302", "17"]); 

哦，你的cron線更改爲： 在/ usr/bin中/ Python的/home/pi/myscript.py