CODEWITHSUNDEEP
bashtclexpect
Ulysses
Ulysses

Reputation: 6015

Unable to print array in bash shell

I have been using tcl shell on windows but while assisting someone on bash found a weird issue:

export SERVER_HOSTNAME=server1
export USERNAME=root
export PASSWORD=pswd
export LOG_FILE="a.log"
export LOG_PATH="$env(LOG_PATH)"
export log_search_pattern="Filterable_data"


/usr/bin/expect<<EOF
set lineNum {}
set SERVER_HOSTNAME "$env(SERVER_HOSTNAME)" 
set USERNAME "$env(USERNAME)" 
set PASSWORD "$env(PASSWORD)" 
set LOG_FILE "$env(LOG_FILE)"   
set log_search_pattern "$env(log_search_pattern)"
set timeout -1  
spawn ssh "$USERNAME@$SERVER_HOSTNAME"

expect  "assword:"  
puts "$expect_out(buffer)"  
parray expect_out
send  "$PASSWORD\r" 
expect "#"
puts "$expect_out(buffer)"
send  "grep -n $log_search_pattern  $LOG_PATH/$LOG_FILE|tail -1\r"  
expect eof
EOF

Now the issue is that the following command:

puts "$expect_out(buffer)"
prints -> (buffer)

But prints the entire buffer contents

parray expect_out

I also tried adding following lines:

set a(1) val1
set a(2) val2
puts $a(1)
puts $a(2)
parray a

It printed:

(1)
(2)
a(1) = val1
a(2) = val2

I tried various combinations to get the puts $a(1) to print val1 but it always printed (1).

What's the correct method to do so?

Upvotes: 0

Views: 145

Answers (1)

Etan Reisner
Etan Reisner

Reputation: 80931

Variables expand in HEREDOCs. If you want to avoid that you need to quote some or all of the opening HEREDOC marker (i.e. <<'EOF') (but not the closing one).

From Here Documents in the bash reference manual:

The format of here-documents is:

<<[-]word
        here-document
delimiter

If any characters in word are quoted, the delimiter is the result of quote removal on word, and the lines in the here-document are not expanded.

So when you have:

puts "$expect_out(buffer)"

in the HEREDOC and expect expect to see that literal string it actually sees:

puts (buffer)

because the shell has removed the quotes and expanded the $expect_out variable for you.

Upvotes: 2

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