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Re: zpty woes

Still doesn't work for me. Below is the modified script and the debug output. 

#!/opt/csw/bin/zsh

set -x

zmodload zsh/zpty

die() {print -r -- $1 >&2; exit 1;}

zpty scppty scp hello.world jvargas@xxxxxxxxxxxxxxxxxxxxxxxxxxx:~/
zpty -t scppty || die "fuck"
zpty -r scppty line "*:" || die "no password asked"
zpty -w scppty "3lp&tbw"
while zpty -r scppty line;
    do
        result+="$line"$'\n'
    done
zpty -d scppty
print $result
I changed my credentials for security. Basically it now hangs waitng for password and doesnt' do anything. -- Jaime 

nerd% ./zpty-test.zsh
+./zpty-test.zsh:5> zmodload zsh/zpty
+./zpty-test.zsh:10> zpty scppty scp hello.world 'luser@host:~/'
+./zpty-test.zsh:11> zpty -t scppty
+./zpty-test.zsh:12> zpty -r scppty line '*:'
+./zpty-test.zsh:13> zpty -w scppty 'TopSecret'
+./zpty-test.zsh:14> zpty -r scppty line
+./zpty-test.zsh:16> result+='1> scp hello.world '\''jvargas@xxxxxxxxxxxxxxxxxxxxxxxxxxx:~/'\'' 

'
+./zpty-test.zsh:14> zpty -r scppty line
+./zpty-test.zsh:16> result+='THIS IS A PROPRIETARY RANDOM HOUSE SYSTEM, RESTRICTED TO AUTHORIZED 

'
+./zpty-test.zsh:14> zpty -r scppty line
+./zpty-test.zsh:16> result+='PERSONNEL AND FOR OFFICIAL, AUTHORIZED RANDOM HOUSE BUSINESS ONLY. 

'
+./zpty-test.zsh:14> zpty -r scppty line
+./zpty-test.zsh:16> result+='ANYONE USING THIS SYSTEM, NETWORK OR DATA IS SUBJECT TO MONITORING 

'
+./zpty-test.zsh:14> zpty -r scppty line
+./zpty-test.zsh:16> result+='AT ANY TIME. ANYONE USING THIS SYSTEM THEREBY EXPRESSLY CONSENTS 

'
+./zpty-test.zsh:14> zpty -r scppty line
+./zpty-test.zsh:16> result+='TO SUCH MONITORING AND IS FURTHER ADVISED THAT ANY EVIDENCE OF 

'
+./zpty-test.zsh:14> zpty -r scppty line
+./zpty-test.zsh:16> result+='CRIMINAL AND/OR OTHERWISE IMPROPER OR UNAUTHORIZED ACTIVITY MAY 

'
+./zpty-test.zsh:14> zpty -r scppty line
+./zpty-test.zsh:16> result+='BE PROVIDED TO LAW ENFORCEMENT OFFICIALS FOR PROSECUTION AND/OR 

'
+./zpty-test.zsh:14> zpty -r scppty line
+./zpty-test.zsh:16> result+='USED BY RANDOM HOUSE AS IT SEES FIT.

'
+./zpty-test.zsh:14> zpty -r scppty line
+./zpty-test.zsh:16> result+='

'
+./zpty-test.zsh:14> zpty -r scppty line


..... it waits forever here.

On May 15, 2008, at 10:50 AM, Stephane Chazelas wrote:



On Thu, May 15, 2008 at 02:18:57PM +0100, Peter Stephenson wrote:


Jaime Vargas wrote:


In the script attached, when trying to follwing line always fails.

     zpty -r scppty line "*:" || echo "no password asked" && exit
It appears that the "password" string from the ssh session is discarded 
by the psuedo terminal.

Is there a way to fix this? or Am I missing something?
Yes and yes, but it's annoying and I spent a few minutes rediscovering 
the arcana.  zpty attempts to read in whole lines, while the password
prompt isn't a whole line. I came across this myself and looked at the code a while ago and it seemed unnecessarily obscure. However, I worked 
around it and don't have time to make it work sensibly in all the
possible cases, so I'm not touching it. (If anyone's interested it's in 
ptyread() in Src/Modules/zpty.c and could definitely do with someone
taking it over; it's pretty much self-contained.)
To work around this, you need to use non-blocking mode, i.e. start with "zpty -b scppty ...". I think (although the code is obscure) that with your "*:" pattern this will work, i.e. although it doesn't block it will 
carry on reading until it gets the password input.  If not, you would
need to delay (the zsh/zselect module allows you to do this in 100ths of 
a second) and retry.  (Waiting for a pattern with noblocking is
effectively a busy wait so even this isn't ideal---you can add the -t
option to the -r command line to test first, but then it *won't* wait
if there's no input and you do have to delay in your script.)


[...]

It works for me without "-b", why would you say "-b" is
necessary?

The problem I've found is that zpty -r doesn't return when the
command in the pty has terminated. A strace -p shows:

read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
[...]

And the other problem I mentionned in another email about the
PS4 output not being correct.

--
Stéphane

On May 15, 2008, at 10:50 AM, Stephane Chazelas wrote:


On Thu, May 15, 2008 at 02:18:57PM +0100, Peter Stephenson wrote:

Jaime Vargas wrote:

In the script attached, when trying to follwing line always fails.

     zpty -r scppty line "*:" || echo "no password asked" && exit
It appears that the "password" string from the ssh session is discarded 
by the psuedo terminal.

Is there a way to fix this? or Am I missing something?
Yes and yes, but it's annoying and I spent a few minutes rediscovering 
the arcana.  zpty attempts to read in whole lines, while the password
prompt isn't a whole line. I came across this myself and looked at the code a while ago and it seemed unnecessarily obscure. However, I worked 
around it and don't have time to make it work sensibly in all the
possible cases, so I'm not touching it. (If anyone's interested it's in 
ptyread() in Src/Modules/zpty.c and could definitely do with someone
taking it over; it's pretty much self-contained.)
To work around this, you need to use non-blocking mode, i.e. start with "zpty -b scppty ...". I think (although the code is obscure) that with your "*:" pattern this will work, i.e. although it doesn't block it will 
carry on reading until it gets the password input.  If not, you would
need to delay (the zsh/zselect module allows you to do this in 100ths of 
a second) and retry.  (Waiting for a pattern with noblocking is
effectively a busy wait so even this isn't ideal---you can add the -t
option to the -r command line to test first, but then it *won't* wait
if there's no input and you do have to delay in your script.)

[...]

It works for me without "-b", why would you say "-b" is
necessary?

The problem I've found is that zpty -r doesn't return when the
command in the pty has terminated. A strace -p shows:

read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
read(12, 0xb7ba04c8, 1)                 = -1 EIO (Input/output error)
[...]

And the other problem I mentionned in another email about the
PS4 output not being correct.

--
Stéphane
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