在.bashrc中回显时，SCP不起作用？

我在Fedora中有两个用户：

1. 瓦尼
2. 根（非常明显！）

我的Wani用户的.bashrc内容是：

# .bashrc
echo "Hello"
# Source global definitions
if [ -f /etc/bashrc ]; then
    . /etc/bashrc
fi

# User specific aliases and functions

现在，登录到root用户后，键入以下命令：

[root@Dell Wani]# touch try.txt
[root@Dell Wani]# service sshd start
[root@Dell Wani]# scp try.txt Wani@localhost:~/
Wani@localhost's password: 
Hello
[root@Dell Wani]# 

现在，我登录Wani，然后键入：

[Wani@Dell ~]$ cat try.txt
cat: try.txt: No such file or directory
[Wani@Dell ~]$ 

现在，我再次登录到root并使用以下命令键入相同的命令-v：

[root@Dell Wani]# scp -v morph.log Wani@localhost:
Executing: program /usr/bin/ssh host localhost, user Wani, command scp -v -t -- .
OpenSSH_5.6p1, OpenSSL 1.0.0j-fips 10 May 2012
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to localhost [127.0.0.1] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /root/.ssh/id_rsa type -1
debug1: identity file /root/.ssh/id_rsa-cert type -1
debug1: identity file /root/.ssh/id_dsa type -1
debug1: identity file /root/.ssh/id_dsa-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.6
debug1: match: OpenSSH_5.6 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.6
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host 'localhost' is known and matches the RSA host key.
debug1: Found key in /root/.ssh/known_hosts:2
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-     with-mic,password
debug1: Next authentication method: gssapi-keyex
debug1: No valid Key exchange context
debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure.  Minor code may provide more information
Credentials cache file '/tmp/krb5cc_0' not found

debug1: Unspecified GSS failure.  Minor code may provide more information
Credentials cache file '/tmp/krb5cc_0' not found

debug1: Unspecified GSS failure.  Minor code may provide more information


debug1: Unspecified GSS failure.  Minor code may provide more information


debug1: Next authentication method: publickey
debug1: Trying private key: /root/.ssh/id_rsa
debug1: Trying private key: /root/.ssh/id_dsa
debug1: Next authentication method: password
Wani@localhost's password: 
debug1: Authentication succeeded (password).
Authenticated to localhost ([127.0.0.1]:22).
debug1: channel 0: new [client-session]
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug1: Sending environment.
debug1: Sending env XMODIFIERS = @im=none
debug1: Sending env LANG = en_US.UTF-8
debug1: Sending command: scp -v -t -- .
Hello
[root@Dell Wani]# debug1: client_input_channel_req: channel 0 rtype exit-status      reply      0
debug1: channel 0: free: client-session, nchannels 1
debug1: fd 0 clearing O_NONBLOCK
debug1: fd 1 clearing O_NONBLOCK
Transferred: sent 1664, received 1976 bytes, in 0.1 seconds
Bytes per second: sent 22961.5, received 27266.8
debug1: Exit status 0

（然后按Enter键）

[root@Dell Wani]# 

谁能说明这里到底发生了什么？为什么文件没有从根目录复制到Wani？

使用echo在.bashrc将打破scp，因为scp期望看到在标准输入/输出频道其协议数据。有关此问题的更多讨论，请参见https://bugzilla.redhat.com/show_bug.cgi?id=20527。

有一些解决方法：

• “交互式”标志的条件（例如case $- in *i*，由三元组建议）
• 使用该tty实用程序检测交互式外壳（例如if tty > /dev/null或if [ -t 0 ]）
• 检查值 $SSH_TTY

我想您应该使用适合您的任何一种。不幸的是，我不知道最好的（最便携式/最可靠）的选择是什么。

要增加nneonneo的选项，您还可以使用带有

if [[ $- =~ "i" ]]

我认为这可能是bash中最清晰的方法。

这对我的作品，
在.bashrc添加第一行：

if [ -z "$PS1" ]; then
    return
fi

/superuser/690735/can-i-tell-if-im-in-an-scp-session-in-my-bashrc

在默认的Ubuntu.bashrc包含下面的代码片段，其已经采取照顾的问题：

# If not running interactively, don't do anything
case $- in
    *i*) ;;
    *) return;;
esac

在中.bashrc，将STDERR用作输出：

echo "# Important Notice" >&2

更新：不要使用它！最近，我们遇到了一个问题，由于的echoSTDERR，（封闭源）工具失败了.bashrc。该工具（使用rcp）根本不会在STDOUT或STDERR上都没有输出。当它得到回声时，它卡住了。获得的经验教训：分别为人类和机器（脚本）建立帐户，或者仅通过停止跟踪.bashrc。

测试交互式外壳的最可移植的方法似乎是：

test -t 0
if [ $? -eq 0 ]
then
    # interactive
    ;
else
    # non-interactive
    ;
fi

nneonneo的解决方案也对我有用。但是由于我的默认外壳是TCSH，因此我必须对修复进行如下修改（在.tcshrc中）：

if ( $?SSH_TTY ) then
    exec /bin/bash
endif

只是想我会为大家的利益分享。

如果您使用的是Red Hat Enterprise Linux（RHEL）或其他版本，请将执行echo或所需操作的脚本拖放到/etc/profile.d/中。

如果您还想要echo语句（来自@Blauhirn的答案），则可以继续将您的echo语句放置在大小写条件之后。

case $- in
    *i*) ;;
    *) return;;
esac

echo "Your Greeting/Warning Message/s here!"

if [ 0 -eq $(shopt -q login_shell; echo $?) ]; then
  echo "do something?"
fi

资源