Expect脚本学习
介绍
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shell脚本可以使用here文档实现某些交互，但无法完成需要用户手动去输入的交互（如passwd、scp）。expect由此而生，可以轻松的完成此类交互。
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expect是一种可以提供“分支和嵌套结构”来引导程序流程的解释型脚本语言，主要运用于自动交互，能够按照脚本内容里面设定的方式与交互式程序进行交互。
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expect可以根据程序的不同提示或反馈内容来进行不同的应答，并且可随时在需要的时候把控制权交给用户，然后再还给脚本。
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expect脚本是基于TCL（Tool Command Language）演变的，其语法与TCL语法类似。
例子
example1
check_passwd()
{
local client_ip=$1
# use timeout to handle the wrong passwd situation, because in the old solution:
# expect {
# *Permission* {exit 1}
# ]* { send exit\r }
# } ;
# In case when the password is wrong but *Permission* wasn't printed out in time, 'exit 1' won't be executed and this expect cmd will exit normally,
# making this password check process fail to function
#
# in the below new solution:
# if passwd is wrong, output will be "Permission denied, please try again.", and "]*" can't be matched, expect will stay waiting there
# and timeout will be triggered after 30 sec, and expect will exit with code 1
expect -c "set timeout 30
spawn ssh ${USER_NAME}@${client_ip}
expect {
*yes/no { send \"yes\r\"; exp_continue }
*assword* { send \"${USER_PASSWD}\r\" }
]* { send \" \r\" };
} ;
expect {
timeout { exit 1 }
]* { send exit\r }
}
expect eof ;
" >/dev/null
}
example2
check_disk_space()
{
local client_ip=$1
local status
# $base_dir_fs and $tmp_dir_fs refers to the Filesystem of ${BASE_DIR} and ${TMP_SRC_DIR}, such as /dev/mapper/centos-root
expect -c "set timeout -1
spawn ssh ${USER_NAME}@${client_ip}
expect {
*yes/no { send \"yes\r\"; exp_continue }
*assword* { send \"${USER_PASSWD}\r\" }
]* { send \" \r\" };
} ;
expect ]* { send \" mkdir -p ${BASE_DIR}; echo RSTATUS:\$?\r \" };
expect -re \"RSTATUS:(\[0-9\]+)\" ;
if { \$expect_out(1,string) != 0 } {
exit 99
}
expect ]* { send \" stdbuf -o0 df -P ${BASE_DIR} | stdbuf -o0 tail -1 | awk '{print \\\$1, \\\$4; fflush()}'\r \" }
expect -re \"fflush.*\r\n(.*) (.*)\r\n\" ;
set base_dir_fs \$expect_out(1,string)
set base_dir_space_KB \$expect_out(2,string)
expect ]* { send \" mkdir -p ${TMP_SRC_DIR}\r \" };
expect ]* { send \" stdbuf -o0 df -P ${TMP_SRC_DIR} | stdbuf -o0 tail -1 | awk '{print \\\$1, \\\$4; fflush()}'\r \" }
expect -re \"fflush.*\r\n(.*) (.*)\r\n\" ;
set tmp_dir_fs \$expect_out(1,string)
set tmp_dir_space_KB \$expect_out(2,string)
if { \"\$base_dir_fs\" == \"\$tmp_dir_fs\" } {
if { \$base_dir_space_KB < 10 * 1024 * 1024 } {
puts \" ERROR: ... \"
puts \" due to install dir and temp dir use the same partition, at least 10GB space be needed \"
puts \" currently only \$base_dir_fs KB is free \"
exit 1
}
} else {
if { \$base_dir_space_KB < 6 * 1024 * 1024 || \$tmp_dir_space_KB < 4 * 1024 * 1024 } {
puts \" ERROR: ... \"
puts \" install dir needs 6GB space, temp dir needs 4GB space \"
puts \" currently install dir: \$base_dir_space_KB KB, temp dir: \$tmp_dir_space_KB KB \"
exit 1
}
}
expect ]* { send \" exit\r \" };
expect eof ;
" >/dev/null
example3
copy_source()
{
local client_ip=$1
expect -c "set timeout -1
spawn ssh ${USER_NAME}@${client_ip}
expect {
*yes/no { send \"yes\r\"; exp_continue }
*assword* { send \"${USER_PASSWD}\r\" }
]* { send \" \r\" };
} ;
expect ]* { send \" rm -fr ${SKYDISCOVERY_DIR}\r \" };
expect ]* { send exit\r };
expect eof ;
" >/dev/null
# to fix wildcard in expect script doesn't work
# http://stackoverflow.com/questions/11092667/wildcard-in-expect-script-doesnt-work
expect -c "set timeout -1
spawn bash -c \"scp -P 22 -r ${CLUSTER_SRC}/* ${USER_NAME}@${client_ip}:${TMP_SRC_DIR}\";
expect {
*yes/no { send \"yes\r\"; exp_continue }
*assword* { send \"${USER_PASSWD}\r\"; exp_continue }
expect eof
} ;
" >/dev/null
return 0
}
example4
install()
{
local client_ip=$1
expect -c "set timeout -1
spawn ssh ${USER_NAME}@${client_ip}
expect {
*yes/no { send \"yes\r\"; exp_continue }
*assword* { send \"${USER_PASSWD}\r\" }
]* { send \" \r\" };
} ;
expect ]* { send \" echo ${SKYDISCOVERY_DIR} > ~/.SkyDiscovery-Installation-Location\r \" }
if { \"${TYPE}\" != \"\" } {
expect ]* { send \" ${TMP_SRC_DIR}/SkyDiscovery-spark -b -t ${TYPE} -p ${SKYDISCOVERY_DIR}; echo RSTATUS:\$?\r \" };
expect -re \"RSTATUS:(\[0-9\]+)\";
if { \$expect_out(1,string) != 0 } {
exit 99
}
} else {
expect ]* { send \" ${TMP_SRC_DIR}/SkyDiscovery-spark -b -p ${SKYDISCOVERY_DIR}; echo RSTATUS:\$?\r \" };
expect -re \"RSTATUS:(\[0-9\]+)\";
if { \$expect_out(1,string) != 0 } {
exit 99
}
}
expect ]* { send exit\r };
expect eof;
"
status="$?"
if [[ "$status" -eq 99 ]]; then
log_error "install SkyDiscovery-spark failed."
return "$status"
fi
return 0
}
完整文章请转到下面link: Expect脚本学习
