How to find whether a particular command has failed inside an sftp script?

Shell Programming and Scripting
1

hi,

how can i know whether a command inside an sftp script has failed or not?

i have a sftp expect script

#!/usr/bin/expect
spawn /usr/bin/sftp abc@ftp.abc.com
expect "sftp>"
send "cd dir\r"
expect "sftp>"
send "mput abc.txt\r"
expect "sftp>"
send "mput def.xls\r"
expect "sftp>"
send "bye\r"
expect eof

suppose there is no directory named "dir" in sftp remote server, then the command at line 4 i.e. cd dir will fail and the script should not proceed further.
how can i do this?

2 
expect {
  "550 dir: No such file or directory" {send "quit\n" ; exit }
  "250 CWD command successful" {exp_continue}
}
3

where should i add this code block? and how it works??

4

Right after the

send "cd dir\r"

You probably have to adjust the "550 .." and "250 CWD..." to your servers response as well.

This works like case/switch. You could add even more "cases".

5

I am not getting how to adjust the return codes. can you give me an example how to do that.. modify the above sample script given by me.

6

Not a trick question; simply change the text to match the exact text your sftp server sends when you do those commands manually...