[英]Unable to read a file and pass into arguments
1)我试图打开一个文件,读取混合数据(整数,字符和字符串)并将其存储到参数中。
1.1),因此sample.txt中的总数为13(不包括args [0])
2)需要从终端“ ./myprog.c <sample.txt”读取文件
这是我的代码,不知道我哪里出错了:
sample.txt:
123 213 110 90 1
hello my friend
boo bleh
a b c
myprog.c:
#include <stdio.h>
int main()
{
int i = 1;
FILE *fstin=fopen(argv[0], "r"); //open the file
if (fstin == NULL) {
puts("Couldn't fopen...");
return -1;
}
//Getting all the inputs from file
while ((fscanf(fstin, "%d", argv[i])) != EOF){
i++;
}
fclose(fstin);
for (i=0; i<10; i++) {
printf("%d\n",argv[i]);
}
return 0;
}
任何帮助是极大的赞赏!
PS:是否有人可以发布完整的解决方案? 将上传到此帖子,并让所有人对此问题进行评论
PPS:请原谅我的编码水平不高,因为我是初学者,并且对C完全陌生。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(int ac, char *av[]){
int i, argc=0;
char **argv=NULL, data[16];
FILE *fstin = stdin;
if(ac == 2){
if(NULL==(fstin = fopen(av[1], "r"))){
puts("Couldn't fopen...");
return -1;
}
}
while (1==fscanf(fstin, "%15s", data)){
argv = realloc(argv, (argc+1)*sizeof(char*));
argv[argc] = malloc(strlen(data)+1);
strcpy(argv[argc++], data);
}
if(ac == 2)
fclose(fstin);
for (i=0; i<argc; ++i) {
printf("%s\n", argv[i]);
}
//deallocate
return 0;
}
您在将文件转移到其他错误的第二点时出错。 实际上,您需要首先编译并需要使可执行文件。
gcc -o my_prog ./myprog.c -Wall
您需要执行以下程序以从c程序读取文件:
./my_prog ./sample.txt
当您不熟悉C编程时,首先进入与文件操作相关的手册页。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, char *argv[]) {
//If command line argument is not inserted then stop operation
if (2 != argc) {
printf("Invalid number of arguments : %d\n", argc);
return -1;
}
int size = 0, ret = 0;
char *data = NULL;
FILE *fp = NULL;
//Open file in read mode given from command line argument
if (NULL != (fp = fopen(argv[1], "r")))
{
//Find size of file
fseek(fp, 0L, SEEK_END);
size = ftell(fp);
fseek(fp, 0L, SEEK_SET);
//if file is empty no need to read it.
if (size > 0)
{
//Data pointer which contains file information
data = (char *) calloc(sizeof(char), size);
if (NULL != data)
{
//Read whole file in one statement
fread(data, sizeof(char), size, fp);
printf("File %s is readed successfully\n", argv[1]);
printf("Data:\n");
printf("%s\n", data);
free(data); data = NULL;
}
else
{
perror("memory allocation failed\n");
ret = -1;
}
}
else
{
printf("File %s is empty\n", argv[1]);
}
fclose(fp); fp = NULL;
}
else
{
perror("File open failed\n");
ret = -1;
}
return ret;
}
现在在您的设置上对其进行测试,如果有任何疑问,请发表评论。
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