CODEWITHSUNDEEP
pythonlinuxbashunixspecial-characters
Apoorv Gupta
Apoorv Gupta

Reputation: 399

Handle invalid characters from filename in unix

I need to do some linux command operations on files having "!" like characters in filename. But whenever I am trying to execute the commands, I am getting below error.

[root@ATD-6000 ~]# cat a!aapoorv.txt
-bash: !aapoorv.txt: event not found

I am executing these commands in python using paramiko module. I can't use raw string r'filestringname', as I am reading string name from db itself.

How to escape/handle these king of characters using python/bash.

Upvotes: 2

Views: 581

Answers (3)

Remi Guan
Remi Guan

Reputation: 22282

try this:

cat a\!aapoorv.txt

or this

cat 'a!aapoorv.txt'

Note that while cat a\!aapoorv.txt works in all shells that implement that csh-style history expansion, cat 'a!aapoorv.txt' doesn't work in csh/tcsh.

for more information, you can see man bash about the QUOTING.

Here is some of that document:

Quoting is used to remove the special meaning of certain characters or words to the shell.

Quoting can be used to disable spe‐cial treatment for special characters, to prevent reserved words from being recognized as such, and to prevent parameter expan‐sion.

And here is the output:

[kevin@Arch test]$ ls
a!aapoorv.txt
[kevin@Arch test]$ cat a\!aapoorv.txt 
Hello, This is a test
[kevin@Arch test]$ cat 'a!aapoorv.txt'
Hello, This is a test

On Python, you don't need to escape the special character, here is a test:

>>> with open('a!aapoorv.txt') as f:
...     f.read()
...     
... 
'Hello, This is a test\n'
>>> with open(r'a!aapoorv.txt') as f:
...     f.read()
...     
... 
'Hello, This is a test\n'
>>>

Upvotes: 2

Alastair McCormack
Alastair McCormack

Reputation: 27704

For Bash, you need to use the escaping methods (single quotes or backslash) described by the other answers.

In Python, you shouldn't need to use raw strings or any other type of escaping to open a file with special chars.

For example, this works fine:

my_f_contents = open("a!aapoorv.txt").read()

Upvotes: 0

sisoft
sisoft

Reputation: 973

use singlequotes ' ':

$ cat 'a!aapoorv.txt'
cat: a!aapoorv.txt: No such file or directory

Upvotes: 0

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