The fseek function is used to set the file pointer position in the file stream. Its syntax is fseek(FILE *stream, long int offset, int whence). Depending on the whence parameter, offset is relative to the beginning of the file (SEEK_SET), the current position (SEEK_CUR), or the end of the file (SEEK_END). If the operation is successful, 0 is returned; otherwise, -1 is returned and the errno variable is set to indicate the error.
Usage of fseek function in C language
The fseek function is used to set file reading and writing in the file stream The position of the pointer. The syntax is:
int fseek(FILE *stream, long int offset, int whence);
Among them:
-
stream
: Pointer to the file stream to be operated on. -
offset
: The offset relative to the file starting from the position specified bywhence
. -
whence
: Specify the position relative tooffset
, there are the following options:-
SEEK_SET
: Start from the beginning of the file. -
SEEK_CUR
: Start from the current file position. -
SEEK_END
: Start from the end of the file.
-
Usage:
-
Locate to the beginning of the file:
fseek(stream, 0, SEEK_SET);
-
Locate to a specific location in the file:
fseek(stream, 100, SEEK_SET); // 定位到文件中的第 101 个字节
-
Move forward from the current position:
fseek(stream, 50, SEEK_CUR); // 从当前位置向前移动 50 个字节
-
Move backward from the end of the file:
fseek(stream, -10, SEEK_END); // 从文件末尾向后移动 10 个字节
Return value:
If the operation is successful, the fseek function returns 0. If the operation fails, -1 is returned and the errno
variable is set to indicate the error.
Example:
The following example demonstrates how to navigate to a specific location in a file and read data:
#include <stdio.h> int main() { FILE *fp; char buffer[100]; // 打开文件 fp = fopen("test.txt", "r"); // 定位到文件中的第 101 个字节 fseek(fp, 100, SEEK_SET); // 从该位置读取数据 fread(buffer, 1, 50, fp); // 关闭文件 fclose(fp); return 0; }
The above is the detailed content of How to use fseek function in C language. For more information, please follow other related articles on the PHP Chinese website!

The C#.NET ecosystem provides rich frameworks and libraries to help developers build applications efficiently. 1.ASP.NETCore is used to build high-performance web applications, 2.EntityFrameworkCore is used for database operations. By understanding the use and best practices of these tools, developers can improve the quality and performance of their applications.

How to deploy a C# .NET app to Azure or AWS? The answer is to use AzureAppService and AWSElasticBeanstalk. 1. On Azure, automate deployment using AzureAppService and AzurePipelines. 2. On AWS, use Amazon ElasticBeanstalk and AWSLambda to implement deployment and serverless compute.

The combination of C# and .NET provides developers with a powerful programming environment. 1) C# supports polymorphism and asynchronous programming, 2) .NET provides cross-platform capabilities and concurrent processing mechanisms, which makes them widely used in desktop, web and mobile application development.

.NETFramework is a software framework, and C# is a programming language. 1..NETFramework provides libraries and services, supporting desktop, web and mobile application development. 2.C# is designed for .NETFramework and supports modern programming functions. 3..NETFramework manages code execution through CLR, and the C# code is compiled into IL and runs by CLR. 4. Use .NETFramework to quickly develop applications, and C# provides advanced functions such as LINQ. 5. Common errors include type conversion and asynchronous programming deadlocks. VisualStudio tools are required for debugging.

C# is a modern, object-oriented programming language developed by Microsoft, and .NET is a development framework provided by Microsoft. C# combines the performance of C and the simplicity of Java, and is suitable for building various applications. The .NET framework supports multiple languages, provides garbage collection mechanisms, and simplifies memory management.

C# and .NET runtime work closely together to empower developers to efficient, powerful and cross-platform development capabilities. 1) C# is a type-safe and object-oriented programming language designed to integrate seamlessly with the .NET framework. 2) The .NET runtime manages the execution of C# code, provides garbage collection, type safety and other services, and ensures efficient and cross-platform operation.

To start C#.NET development, you need to: 1. Understand the basic knowledge of C# and the core concepts of the .NET framework; 2. Master the basic concepts of variables, data types, control structures, functions and classes; 3. Learn advanced features of C#, such as LINQ and asynchronous programming; 4. Be familiar with debugging techniques and performance optimization methods for common errors. With these steps, you can gradually penetrate the world of C#.NET and write efficient applications.

The relationship between C# and .NET is inseparable, but they are not the same thing. C# is a programming language, while .NET is a development platform. C# is used to write code, compile into .NET's intermediate language (IL), and executed by the .NET runtime (CLR).


Hot AI Tools

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

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

Undress AI Tool
Undress images for free

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

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

Dreamweaver Mac version
Visual web development tools

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.
