How to escape a "\" in command parameters

Question

I have a command

path/to/forticlientsslvpn_cli --server <host>:<port> --vpnuser testpass\101

When I run the script, linux puts a space between testpass and 101. I want the script to see "testpass\101" as the username

I hope I make sense

Panki · Answer 1 · 2020-05-05T11:36:08.340

10

This is happening because \ is an escape character.

Either use quoting

path/to/forticlientsslvpn_cli --server <host>:<port> --vpnuser 'testpass\101'

or use an escaped backslash:

path/to/forticlientsslvpn_cli --server <host>:<port> --vpnuser testpass\\101

edited May 05 '20 at 11:36

answered May 05 '20 at 10:52

Panki

Awesome! Thanks, I used the escaped backlash option. – Tlou Rammala May 05 '20 at 11:05
1

You might want to use single quotes to protect backslashes, since they're still special for escaping some characters within double-quotes, e.g. the backslash itself. E.g. a double backslash would be either '\\' or "\\\\". – ilkkachu May 05 '20 at 11:25
Thanks for your addendum, I have edited the answer. @OP: Please mark the answer as "accepted" if it solved your question. – Panki May 05 '20 at 11:36
Hi, could you explain why would \ add an space? I'm having trouble understand it, I think it's the same as testpass'1'01, where does the space come from? – dedowsdi May 05 '20 at 12:09
1

@dedowsdi, there's no space. you're right testpass\101 is the same as testpass101. – ilkkachu May 05 '20 at 12:37

score 7 · Answer 2 · answered May 05 '20 at 11:50

For completeness, with the bash shell and on ASCII based systems, with quoting alone:

'testpass\101' (by far the best)
testpass\\101
"testpass\101" or "testpass\\101" (latter better)
$'testpass\\101'
$'testpass\u005c101' or $'testpass\U0000005c101' (U+005C being the Unicode code point for backslash)
$'testpass\x5c101' (where 0x5C is the byte value of the ASCII encoding of \)
$'testpass\134101' (same in octal)

2 Answers2