C语言-文件操作-10

news2024/11/16 16:53:46

题目：

修改下列程序，用命令行界面代替交互式界面

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#define BUFSIZE 4096

#define SLEN 81

void append(FILE * source,FILE * dest);

char * s_gets(char * st,int n);

int main(){

FILE * fa, * fs;

int files = 0;

char file_app[SLEN];

char file_src[SLEN];

int ch;

puts("Enter name of destination file: ");

s_gets(file_app,SLEN); //输入目标文件名

if((fa = fopen(file_app,"a+")) == NULL){

fprintf(stderr,"cant't open %s\n",file_app);

exit(EXIT_FAILURE);

}

if(setvbuf(fa,NULL,_IOFBF,BUFSIZE) != 0){

fputs("Can't create output buffer\n",stderr);

exit(EXIT_FAILURE);

}

puts("Enter name of first source file (empty line to quit): ");

while(s_gets(file_src,SLEN) && file_src[0] != '\0'){

if(strcmp(file_src,file_app) == 0) fputs("Can't append file to itself\n",stderr);

else if((fs = fopen(file_src,"r")) == NULL) fprintf(stderr,"Can't open %s\n",file_src);

else{

if(setvbuf(fs,NULL,_IOFBF,BUFSIZE) != 0){

fputs("Cant's append file to itself\n",stderr);

continue;

}

append(fs,fa);

if(ferror(fs) != 0) fprintf(stderr,"Error in reading file %s.\n",file_src);

if(ferror(fa) != 0) fprintf(stderr,"Error in writing file %s.\n",file_app);

fclose(fs); //关闭读取文件，继续下一次的读取

files++;

printf("File %s appended.\n",file_src);

puts("Next file (empty line to quit): ");

}

}

printf("Done appending. %d files appended.\n",files);

rewind(fa);

printf("%s contents:\n",file_app);

while((ch = getc(fa)) != EOF) putchar(ch);

puts("Done displaying.");

fclose(fa);

return 0;

}

void append(FILE * source,FILE * dest){

size_t bytes;

static char temp[BUFSIZE];

while(( bytes = fread(temp,sizeof(char),BUFSIZE,source)) > 0){

fwrite(temp,sizeof(char),bytes,dest);

}

}

char * s_gets(char * st,int n){

char * ret_val;

char * find;

ret_val = fgets(st,n,stdin);

if(ret_val){

find = strchr(st,'\n');

if(find) *find = '\0';

else{

while(getchar() != '\n')

continue;

}

}

}

源代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define BUFSIZE 4096
#define SLEN 81
void append(FILE * source,FILE * dest);
char * s_gets(char * st,int n);
int main(int argc,char * argv[]){
    FILE * fa, * fs;
    int files = 0;
    int ch;
    if((fa = fopen(argv[1],"a+")) == NULL){
        fprintf(stderr,"cant't open %s\n",argv[1]);
        exit(EXIT_FAILURE);
    }
    if(setvbuf(fa,NULL,_IOFBF,BUFSIZE) != 0){
        fputs("Can't create output buffer\n",stderr);
        exit(EXIT_FAILURE);
    }
    for(int i = 2;i <= argc-1;i++){
            if(strcmp(argv[i],argv[1]) == 0) fputs("Can't append file to itself\n",stderr);
            else if((fs = fopen(argv[i],"r")) == NULL) fprintf(stderr,"Can't open %s\n",argv[i]);
            else{
                if(setvbuf(fs,NULL,_IOFBF,BUFSIZE) != 0){
                    fputs("Cant's append file to itself\n",stderr);
                    continue;
                }
                append(fs,fa);
                if(ferror(fs) != 0) fprintf(stderr,"Error in reading file %s.\n",argv[i]);
                if(ferror(fa) != 0) fprintf(stderr,"Error in writing file %s.\n",argv[1]);
                fclose(fs);     //关闭读取文件，继续下一次的读取
                files++;
                printf("File %s appended.\n",argv[i]);
            }       
    }
    printf("Done appending. %d files appended.\n",files);
    rewind(fa);
    printf("%s contents:\n",argv[1]);
    while((ch = getc(fa)) != EOF) putchar(ch);
    puts("\nDone displaying.");
    fclose(fa);
    return 0;
}
void append(FILE * source,FILE * dest){
    size_t bytes;
    static char temp[BUFSIZE];
    while(( bytes =  fread(temp,sizeof(char),BUFSIZE,source)) > 0){
        fwrite(temp,sizeof(char),bytes,dest);
    }
}
char * s_gets(char * st,int n){
    char * ret_val;
    char * find;
    ret_val = fgets(st,n,stdin);
    if(ret_val){
        find = strchr(st,'\n');
        if(find) *find = '\0';
        else{
            while(getchar() != '\n')
            continue;
        }
    }
}

演示效果：