在远程服务器上运行的heredoc块中添加等待点

Question

我试图添加一个等待点到我的代码，然后可以手动恢复/解锁。遗憾的是，它并没有像预期的那样起作用。我猜是由于heredoc的工作方式(=stdin)。

有没有人建议另一个仍然使用heredoc的替代方案，因为它使代码非常清晰或任何类似的语法服务于相同的目的。

username=root
host=blah
ssh -t $username@$host <<-EOF_REMOTE_BASH
## set options
set -x
printf ">>> Connected to %s@%sn" "$username" "$host"
## loop and run logic
# this is sample loop only
for i in $(seq 1 2 20); do
## some code
# more code
# ...
# ...
# ...
## Wait until unblocked manually
#  NOT WAITING!
read -s -n 1 -p "Press any key to continue . . ."
done
## Quit server
exit
EOF_REMOTE_BASH

Edit.1:

username=root
host=blah
ssh -t $username@$host "$(cat<<-EOF_REMOTE_BASH
## prep file
src_file=/tmp/test
cat <<- 'EOF' > ${src_file}
10
20
30
EOF
## Loop over file, wait at each iteration
while IFS="" read -r line || [ -n "$line" ]; do
echo "$line"
read -s -n 1 -p "Press any key to continue . . ." && printf "n"
done <"${src_file}"
EOF_REMOTE_BASH
)"

Answer 1

您正在尝试分配一个tty (-t)，但没有从stdin读取。这提供了一个解决方案的线索:

username=root
host=blah
ssh -t $username@$host '
## set options
set -x
printf ">>> Connected to %s@%sn" "$username" "$host"
## loop and run logic
# this is sample loop only
for i in $(seq 1 2 20); do
## some code
# more code
# ...
# ...
# ...
## Wait until unblocked manually
#  NOT WAITING!
read -s -n 1 -p "Press any key to continue . . ." </dev/tty
done
## Quit server
exit
'

关于保留heredoc的方法，请参见:如何在Bash中将heredoc值赋给变量?

你可以这样做:ssh -t $username@host "$cmds"

Answer 2

一种变通方法是将脚本作为ssh参数传递:

(如果您在脚本中定义变量，通常最好使用引号禁用扩展:'EOF_REMOTE_BASH'，在这种情况下，您不会在脚本中引用变量:"$line"，删除)

ssh -t $username@$host "$(cat<<-'EOF_REMOTE_BASH'
read -s -n 1 -p "Press any key to continue . . ."
EOF_REMOTE_BASH
)"