C语言中文件处理的基础
在这里，我们将看到一些用C语言进行的基本文件处理操作。下面列出了这些操作：
写入文件
从文件读取
附加在文件中
写入文件
选择代码以了解我们如何写入文件
范例程式码
#include <stdio.h>
int main() {
FILE *fp;
char *filename = "sample.txt";
char *content = "Hey there! You've successfully created a file with content in c programming language.";
/* open for writing */
fp = fopen(filename, "w");
if( fp == NULL ) {
printf("%s: failed to open. \n", filename);
return -1;
} else {
printf("%s: opened in write mode.\n", filename);
}
/* Write content to file */
fprintf(fp, "%s\n", content);
if( !fclose(fp) )
printf("%s: closed successfully.\n", filename);
return 0;
}输出结果
sample.txt: opened in write mode. sample.txt: closed successfully.
2.从文件读取
选择代码以了解我们如何从文件中读取文件。创建文件(file_read.txt)：
您已经以只读模式使用C编程语言打开了一个文件。
范例程式码
#include <stdio.h>
int main() {
FILE *fp;
char *filename = "file_read.txt";
char ch;
/* open for writing */
fp = fopen(filename, "r");
if (fp == NULL) {
printf("%s does not exists \n", filename);
return;
} else {
printf("%s: opened in read mode.\n\n", filename);
}
while ((ch = fgetc(fp) )!= EOF) {
printf ("%c", ch);
}
if (!fclose(fp))
printf("\n%s: closed.\n", filename);
return 0;
}输出结果
file_read.txt: opened in read mode. You have opened a file using C programming language, in read-only mode. file_read.txt: closed.
3.追加到文件中
选择代码以了解如何将行添加到文件中。
制作文件(file_append.txt)
This text was already there in the file.
范例程式码
#include <stdio.h>
int main() {
FILE *fp;
char ch;
char *filename = "file_append.txt";
char *content = "This text is appeneded later to the file, using C programming.";
/* open for writing */
fp = fopen(filename, "r");
printf("\nContents of %s -\n\n", filename);
while ((ch = fgetc(fp) )!= EOF) {
printf ("%c", ch);
}
fclose(fp);
fp = fopen(filename, "a");
/* Write content to file */
fprintf(fp, "%s\n", content);
fclose(fp);
fp = fopen(filename, "r");
printf("\nContents of %s -\n", filename);
while ((ch = fgetc(fp) )!= EOF) {
printf ("%c", ch);
}
fclose(fp);
return 0;
}输出结果
Contents of file_append.txt - This text was already there in the file. Appending content to file_append.txt... Content of file_append.txt after 'append' operation is - This text was already there in the file. This text is appeneded later to the file, using C programming.