[ale] Weird Perl problem

[Christopher Fowler]

Here is something strange:

Command: ls -ld /root | more

Process 21233 attached
Process 21234 attached
Process 20959 suspended
[pid 21233] read(5, "", 1)              = 0
[pid 21234] open("/dev/tty", O_RDONLY|O_LARGEFILE) = 3
[pid 21234] read(0,  <unfinished ...>
[pid 21233] open("/etc/localtime", O_RDONLY) = 3
[pid 21233] read(3, "TZif\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\4\0\0\0
\4\0"..., 131072) = 1267
[pid 21233] open("/etc/nsswitch.conf", O_RDONLY) = 3
[pid 21233] read(3, "#\n# /etc/nsswitch.conf\n#\n# An ex"..., 131072) =
1686
[pid 21233] read(3, "", 131072)         = 0
[pid 21233] open("/etc/ld.so.cache", O_RDONLY) = 3
[pid 21233] open("/lib/libnss_files.so.2", O_RDONLY) = 3
[pid 21233] read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\320
\32"..., 512) = 512
[pid 21233] open("/lib/libc.so.6", O_RDONLY) = 3
[pid 21233] read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\20
\237"..., 512) = 512
[pid 21233] open("/lib/ld-linux.so.2", O_RDONLY) = 3
[pid 21233] read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\300
\267"..., 512) = 512
[pid 21233] open("/etc/passwd", O_RDONLY) = 3
[pid 21233] read(3, "root:$1$S7wGFvsZ$suYthXHfI2FG3JC"..., 131072) = 104
[pid 21233] open("/etc/group", O_RDONLY) = 3
[pid 21233] read(3, "root:x:0:root\nbin:x:1:root,bin,d"..., 131072) =
613
Process 20959 resumed
Process 21233 detached
[pid 21234] <... read resumed> "", 4096) = 0
Process 20959 suspended
Process 20959 resumed
Process 21234 detached
--- SIGCHLD (Child exited) @ 0 (0) ---
write(2, "bash-3.00# ", 11)             = 11

Command:  ls -ld /rootProcess 21248 attached
Process 20959 suspended
[pid 21248] read(3, "", 1)              = 0
[pid 21248] open("/etc/localtime", O_RDONLY) = 3
[pid 21248] read(3, "TZif\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\4\0\0\0
\4\0"..., 131072) = 1267
[pid 21248] open("/etc/nsswitch.conf", O_RDONLY) = 3
[pid 21248] read(3, "#\n# /etc/nsswitch.conf\n#\n# An ex"..., 131072) =
1686
[pid 21248] read(3, "", 131072)         = 0
[pid 21248] open("/etc/ld.so.cache", O_RDONLY) = 3
[pid 21248] open("/lib/libnss_files.so.2", O_RDONLY) = 3
[pid 21248] read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\320
\32"..., 512) = 512
[pid 21248] open("/lib/libc.so.6", O_RDONLY) = 3
[pid 21248] read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\20
\237"..., 512) = 512
[pid 21248] open("/lib/ld-linux.so.2", O_RDONLY) = 3
[pid 21248] read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\300
\267"..., 512) = 512
[pid 21248] open("/etc/passwd", O_RDONLY) = 3
[pid 21248] read(3, "root:$1$S7wGFvsZ$suYthXHfI2FG3JC"..., 131072) = 104
[pid 21248] open("/etc/group", O_RDONLY) = 3
[pid 21248] read(3, "root:x:0:root\nbin:x:1:root,bin,d"..., 131072) =
613
[pid 21248] write(1, "drwxr-xr-x    2 root     root   "..., 62) = 62
Process 20959 resumed
Process 21248 detached
--- SIGCHLD (Child exited) @ 0 (0) ---
write(2, "bash-3.00# ", 11)             = 11



The difference is that I never see the write() of the single line happen
on the one that was piped. I do when not piped.



On Wed, 2006-10-18 at 08:35 -0400, Paul Cartwright wrote:
> On Wed October 18 2006 8:25 am, Christopher Fowler wrote:
> > Its not specific to perl.  There is something else fundamentally
> > wrong.  
> >
> > ~ $ ls -l / | more
> > ~ $
> >
> > Displays nothing?
> >
> > I just wnet from 2.6.18 -> 2.6.15 kernel on the flash as a test and
> > it made no difference.  I might try the bash shell.
> worked for me using bash:
> 
> I got a listing of my "/" folders
> # uname -a
> Linux linux 2.6.16.21-0.25-default
> 
>