打印和pexpect日志记录

Question

我有一些代码pexpect用于控制进程和代码中的一些打印.主要目标(在这个问题中)是将pexpect输出和打印记录到某个日志文件中.我遇到的问题是pexpect线条(发送和接收的数据)与印刷品混合在一起,没有明显的逻辑.我期待打印字符串和pexpect输出将按它们发出的顺序记录.

示例代码如下:

#!/usr/bin/env python

import pexpect
import time, sys, os

###############################################################################
# Subclass of file object to avoid recording extensive whitespace characters
class CleanFile(file):
    def write (self, text):
        # Remove the whitespaces
        out_text = ''
        # process the backspace properly
        bline = ''
        for c in text:
            if (ord(c) == 0x8):
                if (len(bline) == 0):
                    # Move the file pointer.
                    file.seek(self, -1, os.SEEK_CUR);
                else:
                    bline = bline[:-1]
            else:
                bline += c

        # remove whitespaces from inside a line
        out_text += ''.join(c for c in bline if (ord(c) >= 32 or ord(c) == 10));

        file.write(self, out_text);

###############################################################################
def main():
    fout = CleanFile ("options.log_file.log", 'w')

    sys.stdout = os.fdopen (sys.stdout.fileno(), 'w', 0)
    os.dup2 (fout.fileno(), sys.stdout.fileno());

    p = pexpect.spawn ('tclsh')
    p.logfile = fout

    print "Got into tclsh."
    p.sendline('ls');
    p.expect (['%',pexpect.EOF])

    p.sendline('info tclversion');
    p.expect (['%',pexpect.EOF])

    print "Got the version\n"

    p.sendline('info commands %');
    p.expect (['%',pexpect.EOF])

    p.sendline('exit');

    print 'Ended session'

###############################################################################
if __name__ == "__main__":
    main()

这是输出日志文件的内容:

Got into tclsh.
ls
% lsinfo tclversion

log  options.log_file.log  pexpect_test.py  runtests.py  runtests_steinway.py
% info tclversionGot the version

info commands %

8.4
% info commands %exit
Ended session

有没有办法使pexpect输出和打印输出顺序？

---

更新:基于pexpect 手册页:"请注意,缓冲可能会影响此行为,因为输入以不可预测的块的形式到达".因此它可能会影响日志记录.

Answer 1

如果您可以等到脚本结束才得到结果，则不要为 pexpect 命令设置日志文件，将命令结果保存到变量中，并在最后打印所有内容。

另请注意，您缺少该info commands命令的输出。这可以通过添加一个 Expect() 来等待 tclsh 解释器启动并从命令末尾删除“%”来解决。我以为那是一个错字。

修改main函数为：

def main():                                                          
    fout = CleanFile ("options.log_file.log", 'w')                   

    sys.stdout = os.fdopen (sys.stdout.fileno(), 'w', 0)             
    os.dup2 (fout.fileno(), sys.stdout.fileno());                    

    p = pexpect.spawn ('tclsh')                                      
    p.expect (['%',pexpect.EOF])                                     

    p.sendline('ls');                                                
    p.expect (['%',pexpect.EOF])                                     
    ls = p.before                                                    

    p.sendline('info tclversion');                                   
    p.expect (['%',pexpect.EOF])                                     
    tclversion = p.before                                            

    p.sendline('info commands');                                     
    p.expect (['%',pexpect.EOF])                                     
    commands = p.before                                              

    p.sendline('exit');                                              
    p.close()                                                        

    print "Got into tclsh."                                          
    print ls                                                         
    print tclversion                                                 
    print "Got the version\n"                                        
    print commands                                                   
    print "Ended session"                                            

那么输出是：

Got into tclsh.                                                      
 ls                                                                  
options.log_file.log  pexpect_test.py                                

 info tclversion                                                     
8.5                                                                  

Got the version                                                      

 info commands                                           
tell socket subst open eof pwd glob list pid exec auto_load_index time unknown  
eval lassign lrange fblocked lsearch auto_import gets case lappend proc break v 
ariable llength auto_execok return linsert error catch clock info split array i 
f fconfigure concat join lreplace source fcopy global switch auto_qualify updat 
e close cd for auto_load file append lreverse format unload read package set bi 
nary namespace scan apply trace seek while chan flush after vwait dict continue 
 uplevel foreach lset rename fileevent regexp lrepeat upvar encoding expr unset 
 load regsub history interp exit puts incr lindex lsort tclLog string           

Ended session