fork.c

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>

int main(void)
{
	int i, j;
	int status;
	pid_t pid;

	for (i = 0; i < 6; i++) {
		if ( (pid = fork()) == 0) {
			for (j = 0;; j++) {
			}
		}
	}

	while (wait(&status) > 0) {
	}

	return 0;
}

Makefile

PACKAGE	= fork
SRCS	= $(PACKAGE).c
OBJS	= $(SRCS:.c=.o)

FILES	= README Makefile $(SRCS)
VER	= `date +%Y%m%d`

### command and flags ###
# uncomment when debugging
#DEBUG	= -ggdb -pg # -lefence

LD	= gcc
LDFLAGS	= -g $(DEBUG)
LDLIBS	= -lm

CC	= gcc
CFLAGS	= -g -O2 -Wall $(DEBUG)
CPPFLAGS= -I.

# etc
SHELL	= /bin/sh
RM	= rm -f
PROF	= gprof


### rules ###

.SUFFIXES:
.SUFFIXES: .o .c

all: $(PACKAGE)

$(PACKAGE): $(OBJS)
	$(LD) $(LDFLAGS) $(OBJS) -o $@ $(LDLIBS)

$(OBJS): Makefile

.c.o:
	$(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $@

clean:
	$(RM) $(PACKAGE) $(OBJS)
	$(RM) core gmon.out *~ #*#

tar:
	@echo $(PACKAGE)-$(VER) > .package
	@$(RM) -r `cat .package`
	@mkdir `cat .package`
	@ln $(FILES) `cat .package`
	tar cvf - `cat .package` | gzip -9 > `cat .package`.tar.gz
	@$(RM) -r `cat .package` .package

zip:
	zip -9 $(PACKAGE)-$(VER).zip $(FILES)

run: all