[BRLTTY] problems installing brltty-5.4

John Covici covici at ccs.covici.com
Tue Dec 6 08:31:18 EST 2016


I could not execute the strace properly, I did the following command:
strace -o /tmp/sgml.strace -f -s 100 cat BrlAPI.sgml | sgmlpre
output=txt  | nsgmls -D /usr/share/sgml -D /usr/share/linuxdoc-tools
-ifmttxt > out.1
but it only gave me the first process, did not follow the pipe as
follows
25826 execve("/bin/cat", ["cat", "BrlAPI.sgml"], [/* 52 vars */]) = 0
25826 brk(NULL)                         = 0xe95000
25826 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f2a40e0c000
25826 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
25826 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
25826 fstat(3, {st_mode=S_IFREG|0644, st_size=247181, ...}) = 0
25826 mmap(NULL, 247181, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f2a40dcf000
25826 close(3)                          = 0
25826 open("/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
25826 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0000\10\2\0\0\0\0\0@\0\0\0\0\0\0\0PU\31\0\0\0\0\0\0\0\0\0@\0008\0\v\0@\0C\0B\0\6\0\0\0\5\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0h\2\0\0"..., 832) = 832
25826 fstat(3, {st_mode=S_IFREG|0755, st_size=1664528, ...}) = 0
25826 mmap(NULL, 3770648, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f2a40851000
25826 mprotect(0x7f2a409e0000, 2097152, PROT_NONE) = 0
25826 mmap(0x7f2a40be0000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x18f000) = 0x7f2a40be0000
25826 mmap(0x7f2a40be6000, 14616, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f2a40be6000
25826 close(3)                          = 0
25826 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f2a40dce000
25826 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f2a40dcd000
25826 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f2a40dcc000
25826 arch_prctl(ARCH_SET_FS, 0x7f2a40dcd700) = 0
25826 mprotect(0x7f2a40be0000, 16384, PROT_READ) = 0
25826 mprotect(0x607000, 4096, PROT_READ) = 0
25826 mprotect(0x7f2a40e0d000, 4096, PROT_READ) = 0
25826 munmap(0x7f2a40dcf000, 247181)    = 0
25826 brk(NULL)                         = 0xe95000
25826 brk(0xeb6000)                     = 0xeb6000
25826 open("/usr/lib64/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
25826 fstat(3, {st_mode=S_IFREG|0644, st_size=1966064, ...}) = 0
25826 mmap(NULL, 1966064, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f2a40671000
25826 close(3)                          = 0
25826 fstat(1, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0
25826 open("BrlAPI.sgml", O_RDONLY)     = 3
25826 fstat(3, {st_mode=S_IFREG|0644, st_size=63579, ...}) = 0
25826 fadvise64(3, 0, 0, POSIX_FADV_SEQUENTIAL) = 0
25826 mmap(NULL, 139264, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f2a40dea000
25826 read(3, "<!doctype linuxdoc system>\n<article>\n<title>BrlAPI Reference manual\n<author>\n<name>S\351bastien Hindere"..., 131072) = 63579
25826 write(1, "<!doctype linuxdoc system>\n<article>\n<title>BrlAPI Reference manual\n<author>\n<name>S\351bastien Hindere"..., 63579) = 63579
25826 read(3, "", 131072)               = 0
25826 munmap(0x7f2a40dea000, 139264)    = 0
25826 close(3)                          = 0
25826 close(1)                          = 0
25826 close(2)                          = 0
25826 exit_group(0)                     = ?
25826 +++ exited with 0 +++

On Tue, 06 Dec 2016 02:27:58 -0500,
Dave Mielke wrote:
> 
> [quoted lines by John Covici on 2016/12/04 at 11:13 -0500]
> 
> >I don't know if you remember, but I have been unable to install
> >brltty 5.4 because of a problem with linuxdoc-tools not properly
> >working  with  Brlapi.sgml.  Well, I have found out that it will work
> >if I do not use pipe, but use temporary files instead.  The pipe
> >limits the size  of its input or output to 8192 bytes.  
> 
> But the rest of the pipeline is, in theory, continuing to read from any of its 
> pipes, thus freeing it up to accept more input. So I'm still not understanding 
> why it wouldn't be working.
> 
> I remember this issue, but I no longer remember exactly what the failure was. 
> Could you please post the actual error again?
> 
> Also, if you don't mind generating a huge file, you could send an strace. If 
> you do, you should probably send it to me off-list as it really will be huge. 
> The command would be:
> 
>    strace -o /tmp/sgml.strace -f -s 100 command arg ...
> 
> -o specifies the output file that'll contain the trace.
> -f tells strace to follow forks.
> -s specifies the minimum number of characters to retain for long strings.
> 
> >So, I wonder if we could change the Makefile to use temorary files and this 
> >would solve my problems with minimal impact?
> >
> >The command would be something like this with different file names
> >cat BrlAPI.sgml | sgmlpre output=txt  | nsgmls -D /usr/share/sgml -D
> >/usr/share/linuxdoc-tools -ifmttxt > out.1
> 
> I'd rather avoid doing this sort of thing if at all possible. The only thing 
> that I can think of, at the moment, is that a write to a pipe containing more 
> bytes than the pipe's size is failing. Really, in my opinion, it should be 
> blocking until all the bytes can be written. Maybe there's a way to configure 
> the behaviour and/or increase the pipe size.
> 
> -- 
> Dave Mielke           | 2213 Fox Crescent | The Bible is the very Word of God.
> Phone: 1-613-726-0014 | Ottawa, Ontario   | http://Mielke.cc/bible/
> EMail: Dave at Mielke.cc | Canada  K2A 1H7   | http://FamilyRadio.org/
> _______________________________________________
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> To post a message, send an e-mail to: BRLTTY at mielke.cc
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-- 
Your life is like a penny.  You're going to lose it.  The question is:
How do
you spend it?

         John Covici
         covici at ccs.covici.com


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