C language comprehensive understanding of file operations
Apr 04, 2025 am 10:24 AMC language provides file operation functions, including opening, closing, reading, writing and moving file pointers. These functions support a variety of operations, such as reading data, writing data, and moving it in a file. Use fopen() and fclose() to open and close files, fread() and fwrite() can be used for data reading and writing, and fseek() allows users to move in files. These functions are widely used in practical applications, such as file copying.
C language comprehensive understanding of file operations
File I/O functions
The C language provides several functions to perform file I/O operations:
-
fopen()
: Open a file. -
fclose()
: Close a file. -
fread()
: Read data from a file. -
fwrite()
: Write data to the file. -
fseek()
: Move the file pointer in the file.
Open and close files
// Open the file, "r" means to open FILE in read-only mode *fp = fopen("myfile.txt", "r"); // Close the file fclose(fp);
Read and write files
// Read data from the file char buffer[100]; fread(buffer, sizeof(char), 100, fp); // Write data to the file fwrite("Hello world!", sizeof(char), 12, fp);
Move in files
// Move n bytes forward in the file fseek(fp, n, SEEK_CUR); // Move n bytes backwards in the file fseek(fp, -n, SEEK_END);
Practical case: copying files
#include <stdio.h> int main() { // Open the source file in read-only mode FILE *src_fp = fopen("source.txt", "r"); // Open the target file in write mode FILE *dst_fp = fopen("destination.txt", "w"); char buffer[100]; int bytes_read; // Loop to read and write data until the source file ends while ((bytes_read = fread(buffer, sizeof(char), 100, src_fp)) > 0) { fwrite(buffer, sizeof(char), bytes_read, dst_fp); } // Close the file fclose(src_fp); fclose(dst_fp); return 0; }
The above is the detailed content of C language comprehensive understanding of file operations. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

C language data structure: The data representation of the tree and graph is a hierarchical data structure consisting of nodes. Each node contains a data element and a pointer to its child nodes. The binary tree is a special type of tree. Each node has at most two child nodes. The data represents structTreeNode{intdata;structTreeNode*left;structTreeNode*right;}; Operation creates a tree traversal tree (predecision, in-order, and later order) search tree insertion node deletes node graph is a collection of data structures, where elements are vertices, and they can be connected together through edges with right or unrighted data representing neighbors.

The readdir function in the Debian system is a system call used to read directory contents and is often used in C programming. This article will explain how to integrate readdir with other tools to enhance its functionality. Method 1: Combining C language program and pipeline First, write a C program to call the readdir function and output the result: #include#include#include#includeintmain(intargc,char*argv[]){DIR*dir;structdirent*entry;if(argc!=2){

The truth about file operation problems: file opening failed: insufficient permissions, wrong paths, and file occupied. Data writing failed: the buffer is full, the file is not writable, and the disk space is insufficient. Other FAQs: slow file traversal, incorrect text file encoding, and binary file reading errors.

C language multithreading programming guide: Creating threads: Use the pthread_create() function to specify thread ID, properties, and thread functions. Thread synchronization: Prevent data competition through mutexes, semaphores, and conditional variables. Practical case: Use multi-threading to calculate the Fibonacci number, assign tasks to multiple threads and synchronize the results. Troubleshooting: Solve problems such as program crashes, thread stop responses, and performance bottlenecks.

ABI compatibility in C refers to whether binary code generated by different compilers or versions can be compatible without recompilation. 1. Function calling conventions, 2. Name modification, 3. Virtual function table layout, 4. Structure and class layout are the main aspects involved.

Algorithms are the set of instructions to solve problems, and their execution speed and memory usage vary. In programming, many algorithms are based on data search and sorting. This article will introduce several data retrieval and sorting algorithms. Linear search assumes that there is an array [20,500,10,5,100,1,50] and needs to find the number 50. The linear search algorithm checks each element in the array one by one until the target value is found or the complete array is traversed. The algorithm flowchart is as follows: The pseudo-code for linear search is as follows: Check each element: If the target value is found: Return true Return false C language implementation: #include#includeintmain(void){i

How to output a countdown in C? Answer: Use loop statements. Steps: 1. Define the variable n and store the countdown number to output; 2. Use the while loop to continuously print n until n is less than 1; 3. In the loop body, print out the value of n; 4. At the end of the loop, subtract n by 1 to output the next smaller reciprocal.

C language functions include definitions, calls and declarations. Function definition specifies function name, parameters and return type, function body implements functions; function calls execute functions and provide parameters; function declarations inform the compiler of function type. Value pass is used for parameter pass, pay attention to the return type, maintain a consistent code style, and handle errors in functions. Mastering this knowledge can help write elegant, robust C code.
