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Full Discussion: write() / read() syntax
Special Forums IP Networking write() / read() syntax Post 302419433 by jim mcnamara on Friday 7th of May 2010 06:59:09 AM
Old 05-07-2010
1. use send() & recv() on sockets they are meant for that and return more meaningfull error codes.

2. the syntax for write does not include a format string like:"%d %d" - the same is true for read
example:
Code:
retval=write(newsockfd, buffer, number_bytes_to_write);
retval=read (newsockfd, buffer, number_bytes_to_read);
retval=send(sockfd, buffer, bufferlen, 0);
retval=recv(newsockfd, buffer, bufferlen, 0);

You code cannot have compiled at all. Always check the return code from system calls. The 0 (flags argument) for recv lets you do neat stuff like MSG_PEEK.
 

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LEARN ABOUT OSF1

cfg_subsysop

cfg_subsysop(9r)														  cfg_subsysop(9r)

NAME

       cfg_subsysop - Kernel routine used to perform subsystem-defined operations

SYNOPSIS

       #include <sys/sysconfig.h> ); cfg_status_t cfg_subsysop(
	       char *subsys,
	       cfg_op_t op,
	       caddr_t indata,
	       size_t insize,
	       caddr_t outdata,
	       size_t outsize );

ARGUMENTS

       Name  of  the  subsystem.   Value of the operation code defined by the subsystem to be preformed. Subsystem codes are from 100 to 999.  The
       input data to the subsystem's configure routine. This buffer is allocated by the caller. Its contents are filled in  by	the  caller.   The
       length of the data in bytes in the indata argument.  The output data of the operation. This buffer is allocated by the caller, but its con-
       tents are filled in by the system's configure routine.  The length in bytes of the output data in the output buffer.

DESCRIPTION

       The cfg_subsysop( ) routine performs a subsystem defined operation. The semantics of the operation are defined by the subsystem and  imple-
       mented in the subsystem's configure routine.

RETURN VALUES

       This  routine  returns  32 bit status values of type cfg_status_t composed of  subsystem status and framework status segments. The upper 16
       bits is the subsystem status (CFG_STATUS_SUBSYS) and the lower 16 bits is the frame status (CFG_STATUS_FRAME). The return values are  orga-
       nized as follows:[Upper subsystem 16 bits][Lower framework 16 bits]

       The  subsystem status is returned by the subsystem's configure routine and can be any error in errno.h. The framework status is returned by
       the configuration framework and the possible values are defined in <sys/sysconfig.h> as CFG_FRAME_Exxx. A completely  successful  operation
       has ESUCCESS(0) returned in both status segments.

       See the cfg_errno(9r) and errno(2) reference pages for more details about error numbers and status.

EXAMPLE

	      char		      indata[IN_SZ];
	      char		      outdata[OUT_SZ];
	      cfg_status_t	      retval;

	      /***************************************************/
	      /*   Call the cfg_subsysop routine		*/

	      retval = cfg_subsysop("lvm", CLEAN_UP, indata,IN_SZ, outdata, OUT_SZ);

	      if (retval != CFG_SUCCESS)
		 print_error(retval);

SEE ALSO

       Kernel Interfaces: cfg_reconfigure(9r), cfg_query(9r), cfg_unconfigure(9r), cfg_configure(9r), cfg_errno(9r)

       Tru64 UNIX: errno(2), cfg_subsys_op(3)

																  cfg_subsysop(9r)
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