SFTP dollar sign issue when sending password in Unix

Question

I need to SFTP a file to a server. The password has a dollar sign $ and I need to escape it.

I tried with Perl and sed commands I am able to replace but the string following $ is not getting added.

Example:

echo "Np4$g" | perl -pe 's/$/\\\\\$/g'

output

Np4\\$

It supposed to be Np4\\$g, but g is not getting appended.

Code:

/usr/bin/expect <<EOF
set timeout -1
spawn sftp -C -oPort=$port $sftp_username@$host_name
expect "password:"
send "$password\r"
expect "sftp>"
cd $remote_dir
send "mput *.txt\r"
expect "sftp>"
send

/usr/bin/expect <" cd $remote_dir send "mput *.txt\r" expect "sftp>" send "quit\r" EOF — mithun, May 07 '17 at 16:02
See: [Difference between single and double quotes in bash](http://stackoverflow.com/q/6697753/3776858) — Cyrus, May 07 '17 at 16:08

score 2 · Answer 1 · edited May 07 '17 at 19:31

Your command

echo "Np4$g" | perl -pe 's/$/\\\\\$/g'

is failing for two reasons

In "Np4$g", the shell is interpolating the variable g into the double-quoted string. It probably isn't defined so it is replaced with nothing, and you are passing just Np4 to perl. You need to use single quotes to prevent the interpolation
In the Perl substitution s/$/\\\\\$/g the $ in the pattern matches the end of the string, not a literal dollar. That means Np4 is changed to Np4\\$. You need to escape the dollar sign in the pattern to get it to match a literal $

This will work correctly

echo 'Np4$g' | perl -pe 's/\$/\\\$/g'

output

Np4\$g

score 1 · Answer 2 · answered May 07 '17 at 16:07

1

I suggest to not escape and replace

"Np4$g"

by

'Np4$g'

answered May 07 '17 at 16:07

Cyrus

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SFTP dollar sign issue when sending password in Unix

Example:

output

Code:

2 Answers2

output