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Re: how to debug this strange load problem
From: |
Przemek Klosowski |
Subject: |
Re: how to debug this strange load problem |
Date: |
Tue, 29 Aug 2006 15:19:15 -0400 (EDT) |
I compared what happens on my system when I try to read Frank's file
containing the string "103\n104\n105" (three numbers on three lines,
with no terminating newline) with Frank's strace results:
-------------my system-----------------------
------------Frank---------------------------
open("/tmp/d", O_RDONLY) = 3 open("test2.txt",
O_RDONLY|O_LARGEFILE) = 3
close(3) = 0 close(3)
= 0
futex(0x3b8b31fc60, FUTEX_WAKE, 2147483647) = 0
brk(0x19f3000) = 0x19f3000
open("/tmp/d", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0664, st_size=11, ...}) = 0
lseek(3, 0, SEEK_SET) = 0
read(3, "103\n104\n", 8) = 8
close(3) = 0
open("/tmp/d", O_RDONLY) = 3 open("test2.txt",
O_RDONLY|O_LARGEFILE) = 3
read(3, "103\n104\n105", 8191) = 11 read(3, "103\n104\n105",
8191) = 11
lseek(3, 0, SEEK_SET) = 0 _llseek(3, 0, [0],
SEEK_SET) = 0
read(3, "103\n104\n105", 8191) = 11 read(3, "103\n104\n105",
8191) = 11
read(3, "", 8191) = 0 read(3, "", 8191)
= 0
lseek(3, 0, SEEK_SET) = 0 _llseek(3, 0, [0],
SEEK_SET) = 0
lseek(3, 124, SEEK_SET) = 124 _llseek(3, 124, [124],
SEEK_SET) = 0
read(3, "", 8191) = 0 read(3, "", 8191)
= 0
lseek(3, 0, SEEK_SET) = 0 _llseek(3, 0, [0],
SEEK_SET) = 0
read(3, "103\n104\n105", 8191) = 11 read(3, "103\n104\n105",
8191) = 11
read(3, "", 8191) = 0 read(3, "", 8191)
= 0
close(3) = 0 close(3)
= 0
open("/tmp/d", O_RDONLY) = 3
read(3, "103\n104\n105", 8191) = 11
close(3) = 0
open("/tmp/d", O_RDONLY) = 3
lseek(3, 0, SEEK_CUR) = 0
read(3, "103\n104\n105", 8191) = 11
read(3, "", 8191) = 0
lseek(3, 0, SEEK_SET) = 0
read(3, "103\n104\n105", 8191) = 11
read(3, "", 8191) = 0
close(3) = 0
read(0, "", 4096) = 0
Clearly, the I/O libraries are different, but the behavior seems to be similar,
except for the
third seek (lseek(3, 124, SEEK_SET)) which for some weird reason seeks to
position 124 in this
11-byte file. On Frank's system it seems to result in going to offset 0 but the
subsequent read
returns an empty string (compare with the next two lines, where it asks to go
to zero, returns
zero and reads the whole file again.
Frank---what is your Linux flavor/version again?
Also, Frank---if the 'load test2.txt' read worked, it would have created an
octave variable test2:
octave:1> load test2.txt
octave:2> test2
test2 =
103
104
105
Did you check that particular variable name?
- how to debug this strange load problem, frank wang, 2006/08/29
- Re: how to debug this strange load problem, David Bateman, 2006/08/29
- Re: how to debug this strange load problem, frank wang, 2006/08/29
- Re: how to debug this strange load problem, John W. Eaton, 2006/08/29
- Re: how to debug this strange load problem, frank wang, 2006/08/29
- Re: how to debug this strange load problem, John W. Eaton, 2006/08/29
- Re: how to debug this strange load problem, frank wang, 2006/08/30
- Re: how to debug this strange load problem, John W. Eaton, 2006/08/30
- Re: how to debug this strange load problem, frank wang, 2006/08/31
- Re: how to debug this strange load problem,
Przemek Klosowski <=
- Re: how to debug this strange load problem, frank wang, 2006/08/29
Re: how to debug this strange load problem, Joe Koski, 2006/08/29