Hey guys,
I'm given this bit of code, but, I'm having some problems executing it with the functions I've defined so far. I'm suppose to define the funtions "parse" and "execute." Parse splits the command in buf into individual arguments. It strips whitespace, replacing those it finds with NULLS... (3 Replies)
Hi, so I've got this program("main") that fork executes another ("user"). These programs communicate through fifos.
One communication is a spawn call, where user passes an executable, main forks and executes it. So, I'm keeping track of all my processes using a task table. After the fork (for... (6 Replies)
I am trying to figure out why when i have the following code
int main( { printf("0\n"); fork(); printf("1\n"); exit(0);}
and type in the shell
a.out | cat
the output of this program is
0
1
0
1
instead of
0
1
1
does anyone know? (3 Replies)
Hello *NIX gurus,
I have a slight perplexing problem with multiple forks giving different results... Here is the deal.
From what I undestand, a fork() call starts executing from the next instruction that follows the fork() call. That means it inherits the PC counter register value of the... (4 Replies)
# include <stdio.h>
# include <fcntl.h>
# include <stdlib.h>
# include <sys/stat.h>
int main(int argc, char *argv)
{
int fRead, fPadded, padVal;
int btRead;
int BUFFSIZE = 512;
char buff;
if (argc != 4)
{
printf ("Please provide all of the... (3 Replies)
I am using the while-loop to read a file.
The file has lines with null-terminated strings (words, actually.)
What I have by that reading - just a first word up to '\0'!
I need to have whole string up to 'new line' - (LF, 10#10, 16#A)
What I am doing wrong?
#make file 'grb' with... (6 Replies)
Hello All,
i am a newbie and need some help when reading a csv file in a bourne shell script. I want to read 10 lines, then wait for a minute and then do a reading of another 10 lines and so on in the same way. I want to do this till the end of file.
Any inputs are appreciated
... (3 Replies)
Hi,
I am facing issues with the below:
I have a lookup file say lookup.lkp.This lookup.lkp file contains strings delimited by comma(,).
Now i want to read this command from file and execute it.
So my code below is :
Contents in the lookup.lkp file is :
c_e,m,a,`cd $BOX | ls cef_*|tail... (7 Replies)
all,
i've been reading to try and get an abstract idea of the process effeciency of commands , sed, bash, perl, awk, find, grep, etc
which processes will spawn?, fork?, launch subshell?, etc and under what conditions?
how do you know which commands have the faster and better stdio... (2 Replies)
Discussion started by: f77hack
2 Replies
LEARN ABOUT NETBSD
setbuffer
SETBUF(3) BSD Library Functions Manual SETBUF(3)NAME
setbuf, setbuffer, setlinebuf, setvbuf -- stream buffering operations
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <stdio.h>
void
setbuf(FILE * restrict stream, char * restrict buf);
void
setbuffer(FILE *stream, char *buf, size_t size);
int
setlinebuf(FILE *stream);
int
setvbuf(FILE * restrict stream, char * restrict buf, int mode, size_t size);
DESCRIPTION
The three types of buffering available are unbuffered, block buffered, and line buffered. When an output stream is unbuffered, information
appears on the destination file or terminal as soon as written; when it is block buffered many characters are saved up and written as a
block; when it is line buffered characters are saved up until a newline is output or input is read from any stream attached to a terminal
device (typically stdin). The function fflush(3) may be used to force the block out early. (See fclose(3).)
Normally all files are block buffered. When the first I/O operation occurs on a file, malloc(3) is called, and an optimally-sized buffer is
obtained. If a stream refers to a terminal (as stdout normally does) it is line buffered. The standard error stream stderr is initially
unbuffered.
The setvbuf() function may be used to alter the buffering behavior of a stream. The mode parameter must be one of the following three
macros:
_IONBF unbuffered
_IOLBF line buffered
_IOFBF fully buffered
The size parameter may be given as zero to obtain deferred optimal-size buffer allocation as usual. If it is not zero, then except for
unbuffered files, the buf argument should point to a buffer at least size bytes long; this buffer will be used instead of the current buffer.
(If the size argument is not zero but buf is NULL, a buffer of the given size will be allocated immediately, and released on close. This is
an extension to ANSI C; portable code should use a size of 0 with any NULL buffer.)
The setvbuf() function may be used at any time, but may have peculiar side effects (such as discarding input or flushing output) if the
stream is ``active''. Portable applications should call it only once on any given stream, and before any I/O is performed.
The other three calls are, in effect, simply aliases for calls to setvbuf(). Except for the lack of a return value, the setbuf() function is
exactly equivalent to the call
setvbuf(stream, buf, buf ? _IOFBF : _IONBF, BUFSIZ);
The setbuffer() function is the same, except that the size of the buffer is up to the caller, rather than being determined by the default
BUFSIZ. The setlinebuf() function is exactly equivalent to the call:
setvbuf(stream, (char *)NULL, _IOLBF, 0);
RETURN VALUES
The setvbuf() function returns 0 on success, or EOF if the request cannot be honored (note that the stream is still functional in this case).
The setlinebuf() function returns what the equivalent setvbuf() would have returned.
SEE ALSO fclose(3), fopen(3), fread(3), malloc(3), printf(3), puts(3)STANDARDS
The setbuf() and setvbuf() functions conform to ANSI X3.159-1989 (``ANSI C89'').
BUGS
The setbuffer() and setlinebuf() functions are not portable to versions of BSD before 4.2BSD. On 4.2BSD and 4.3BSD systems, setbuf() always
uses a suboptimal buffer size and should be avoided.
BSD June 4, 1993 BSD