和菜鸟一起深入学习国嵌实验之文件编程

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>

void create_file(char *filename)
{
//create a file
if(creat(filename, 0666)< 0)
{
printf("createfile %s failure\n", filename);
return;
}
else
{
printf("createfile %s success!\n", filename);
}
}

int main(int argc, char *argv[])
{
if(argc < 2)
{
printf("youhave't input the filename, please try again\n");
exit(1);
}

create_file(argv[1]);

return 0;
}

CC = gcc

CURTDIR = $(shell pwd)
TARGET = file_create

%.o:%.c
$(CC) -c $(EXTRAFLAGS) $<-o $@
%.o:%.S
$(CC) -c $(EXTRAFLAGS) $<-o $@

.PHONY: all clean

$(TARGET): $(TARGET).o
$(CC)  -o $@ $^

clean:
rm -rf $(TARGET) $(TARGET).o

eastmoon@eastmoon-virtual-machine:~/work/guoqian/1/1.5$ make
gcc -c  file_create.c -ofile_create.o
gcc  -o file_createfile_create.o

eastmoon@eastmoon-virtual-machine:~/work/guoqian/1/1.5$ ls
file_create file_create.c  file_create.o  Makefile

eastmoon@eastmoon-virtual-machine:~/work/guoqian/1/1.5$./file_create file_cre
create file file_cre success!

eastmoon@eastmoon-virtual-machine:~/work/guoqian/1/1.5$ ll
鎬荤敤閲?40
drwxr-xr-x 2 eastmoon eastmoon 4096 2013-01-29 19:39 ./
drwxr-xr-x 8 eastmoon eastmoon 4096 2013-01-29 19:29 ../
-rw-r--r-- 1 eastmoon eastmoon    0 2013-01-29 19:39 file_cre
-rwxr-xr-x 1 eastmoon eastmoon 7232 2013-01-29 19:38 file_create*
-rw-r--r-- 1 eastmoon eastmoon  571 2013-01-29 19:38 file_create.c
-rw-r--r-- 1 eastmoon eastmoon 1204 2013-01-29 19:38 file_create.o
-rw------- 1 eastmoon eastmoon 12288 2013-01-29 19:39 .file.txt.swp
-rw-r--r-- 1 eastmoon eastmoon  237 2013-01-29 19:31 Makefile

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define BUFFER_SIZE 1024

int main(int argc, char *argv[])
{
FILE *from_fd;
FILE *to_fd;
long file_len = 0;
char buffer[BUFFER_SIZE];
char *ptr;

if(argc != 3)
{
printf("Usage: %s form file tofile\n", argv[0]);
exit(1);
}

//open source file
if((from_fd =fopen(argv[1], "rb")) == NULL)
{
printf("Open %sError\n", argv[1]);
exit(1);
}

//create dest file
if((to_fd = fopen(argv[2],"wb")) == NULL)
{
printf("Open %sError\n", argv[1]);
exit(1);
}

//test the file size
fseek(from_fd, 0L,SEEK_END);
file_len = ftell(from_fd);
fseek(from_fd, 0L,SEEK_SET);

printf("from filesize is %ld\n", file_len);

//copy the file
while(!feof(from_fd))
{
fread(buffer,BUFFER_SIZE, 1, from_fd);
if(BUFFER_SIZE >=file_len)
{
fwrite(buffer,file_len, 1, to_fd);
}
else
{
fwrite(buffer,BUFFER_SIZE, 1, to_fd);
file_len =file_len - BUFFER_SIZE;
}
bzero(buffer,BUFFER_SIZE);
}
fclose(from_fd);
fclose(to_fd);

return 0;
}

CC = gcc

CURTDIR = $(shell pwd)
TARGET = file_cp

%.o:%.c
$(CC) -c $(EXTRAFLAGS) $<-o $@
%.o:%.S
$(CC) -c $(EXTRAFLAGS) $<-o $@

.PHONY: all clean

$(TARGET): $(TARGET).o
$(CC)  -o $@ $^

clean:
rm -rf $(TARGET) $(TARGET).o

eastmoon@eastmoon-virtual-machine:~/work/guoqian/1/1.5$ make
gcc -c  file_cp.c -o file_cp.o
gcc  -o file_cp file_cp.o

eastmoon@eastmoon-virtual-machine:~/work/guoqian/1/1.5$./file_cp  file_cp.c file_test.c
from file size is 1241

eastmoon@eastmoon-virtual-machine:~/work/guoqian/1/1.5$ ll
鎬荤敤閲?44
drwxr-xr-x 2 eastmoon eastmoon 4096 2013-01-29 19:28 ./
drwxr-xr-x 7 eastmoon eastmoon 4096 2013-01-29 19:11 ../
-rwxr-xr-x 1 eastmoon eastmoon 7472 2013-01-29 19:27 file_cp*
-rw-r--r-- 1 eastmoon eastmoon 1241 2013-01-29 19:26 file_cp.c
-rw-r--r-- 1 eastmoon eastmoon 1868 2013-01-29 19:27 file_cp.o
-rw-r--r-- 1 eastmoon eastmoon 1241 2013-01-29 19:28 file_test.c
-rw------- 1 eastmoon eastmoon 12288 2013-01-29 19:28 .file.txt.swp
-rw-r--r-- 1 eastmoon eastmoon  233 2013-01-29 19:27 Makefile

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<fcntl.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<time.h>

intmain(int argc, char *argv[])
{
struct tm *ptr;
time_t lt;

//get current time
lt = time(NULL);

//turn to the native time
ptr = localtime(<);

//print the time as native time
printf("%s\n", asctime(ptr));

printf("%s\n", ctime(<));

return 0;
}

CC =gcc

CURTDIR= $(shell pwd)
TARGET= time

%.o:%.c
$(CC) -c $(EXTRAFLAGS) $< -o $@
%.o:%.S
$(CC) -c $(EXTRAFLAGS) $< -o $@

.PHONY:all clean

$(TARGET):$(TARGET).o
$(CC) -o $@ $^

clean:
rm -rf $(TARGET) $(TARGET).o

eastmoon@eastmoon-virtual-machine:~/work/guoqian/1/1.7$make
gcc-c  time.c -o time.o
gcc  -o time time.o

eastmoon@eastmoon-virtual-machine:~/work/guoqian/1/1.7$ls
Makefile  time time.c  time.o

eastmoon@eastmoon-virtual-machine:~/work/guoqian/1/1.7$./time
TueJan 29 19:45:46 2013

TueJan 29 19:45:46 2013