fgets | 易学教程

fgets() doesn't function as expected [duplicate]

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问题 This question already has answers here : fgets doesn't work after scanf (7 answers) scanf() leaves the new line char in the buffer (4 answers) Closed 2 years ago . This is my code int main(){ int N,i,radius,diameter,count =0; char str[20]; char color[N][20]; printf("Get the num : "); scanf("%d",&N); printf("Enter the mesage\n"); for(i=0;i<N;i++){ fgets(color[i],20,stdin); } for(i=0;i<N;i++){ printf("%s",color[i]); } return 0; } Given inputs are: N = 3 red 50, 50 green, blue 50 Here the

Why is fgets getting stuck on carriage return \r?

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问题 I'm new to the forum and to c in general, so please bear with me. I'm trying to write a c program that takes a text file and parses all words and characters, then saves them to an output text file. I'm using C99, Windows 7-64bit, MinGW, notepad, notepad++, and ASNI format for txt files. I've read that fgets() is better to use than fscanf for reading input because it has buffer overflow protection, so I decided to try using it, but it's having issues with some punctuation in the test file (I

Sending arbitrary bytes to fgets from stdin [closed]

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问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 3 years ago . I'm prompting for a user supplied string using fgets(user_input, input_len, stdin). How can I send, for instance, the byte represented by hex \x04 to the program? 回答1: You can do $ echo -n -e '\x04' | your-program NOTE: On POSIX echo only octal values are allowed. 回答2: If you can

writing and reading within a fork - C

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问题 The exercise is simple. The father process lets me write my name and surname in a file. The son process waits 5 seconds, then reads and displays it. I can't use the #wait() function. #include <cstdlib> #include <stdio.h> #include <string.h> #include <stdlib.h> #include <unistd.h> int main(int argc, char** argv) { char name[20]; char surname[20]; char outp[50]; // The file pointer FILE *file; // Open the file in write mode file = fopen("dati.txt", "w+"); pid_t pid; pid=fork(); if(pid>0){

How to use fgets() to safely handle user input more than once

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问题 I'm sorry if I duplicate, but I have tried EVERYTHING, and I can't figure out why this code keeps breaking. The highest-priority goal was to make this code handle input safely, or just anything that the user can type into the console, without it breaking. However, I also need it to be able to run more than once. fgets() won't let me do that since it keeps reading '\n' somewhere and preventing me from entering input more than once when it hits the end of the do/while loop. I have tried

Unexpected repitition using fgets and sscanf

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问题 Here is a part of my code. The aim of gets and sscanf is to scan three variables separated by exactly one space. If passed, then output the instruction again. Otherwise, output error and exit program. I want to use 7 length char array to limit the number in the line, getting format like 'g 3 3' only. But it seems something wrong in my code. #include <stdio.h> int main (void) { char line[7]; char command; int x, y; while(1){ /* problem: g 4 4 or g 4 4 can also pass */ fgets(line, 7, stdin);

Atitit 文件读取规范目录 1.1. 以fgetss取代fgets读取一行并过滤掉 HTML 和 PHP 标记。 1 1.2. 3. 以二进制读取 fread取代fgets 1 1.3. 4.

阅读更多关于 Atitit 文件读取规范目录 1.1. 以fgetss取代fgets读取一行并过滤掉 HTML 和 PHP 标记。 1 1.2. 3. 以二进制读取 fread取代fgets 1 1.3. 4.

Atitit 文件读取规范目录 1.1. 以fgetss取代fgets读取一行并过滤掉 HTML 和 PHP 标记。 1 1.2. 3. 以二进制读取 fread取代fgets 1 1.3. 4.将整个文件读入到一个字符串的方法 file_get_contents() 2 1.4. 5.将整个文件读入到一个数组中返回 file() 2 以fgetss取代fgets读取一行并过滤掉 HTML 和 PHP 标记。 fgetss() 函数从打开的文件中读取一行并过滤掉 HTML 和 PHP 标记。与 fgets() 相同，不同的是 fgetss 尝试从读取的文本中去掉任何 HTML 和 PHP 标记。例子： 1 2 3 4 5 6 <?php $file = fopen ( "test.htm" , "r" ); echo fgetss ( $file ); fclose( $file ); ?> 　　当然也可以通过传递第三个参数来指定哪些标记是允许输出的： 1 2 3 4 5 6 7 <?php $file = fopen ( "test.htm" , "r" ); echo fgetss ( $file ,1024, "<p>,<b>" ); //<p>和<b>标记将不会被过滤 fclose( $file ); ?> 　详细信息参考： http://www.w3school

Reading from stdin using fgets()

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问题 I'm new to C programming and I'm currently trying to read a line from stdin using fgets(), but I'm having trouble with memory allocation since I'm using a char* to point to the string I want to read. When I execute the file it reports a segmentation fault. This is the function I'm using: char *read_line(char *line){ printf("%s",PROMPT); line = (char*)malloc(sizeof(char)*500); fgets(line,sizeof(line),stdin); printf("%s","pasa el fgets"); return line; } And my main: void main(){ char line0;

Why is fgets() and strncmp() not working in this C code for string comparison?

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问题 This is a very fun problem I am running into. I did a lot of searching on stack overflow and found others had some similar problems. So I wrote my code accordingly. I originally had fscan() and strcmp() , but that completely bombed on me. So other posts suggested fgets() and strncmp() and using the length to compare them. I tried to debug what I was doing by printing out the size of my two strings. I thought, maybe they have /n floating in there or something and messing it up (another post

why when we write \n in the file it converts into \r\n combination?

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问题 I read this concept from book that when we attemp to write \n to the file using fputs(), fputs() converts the \n to \r\n combination and then if we read the same line back using fgets () the reverse conversion happens means \r\n back convert to \n. I don't get that what is the purpose behind this? 回答1: It is because Windows (and MS-DOS) text files are supposed to have lines ending in \r\n, and portable C programs are supposed to simply use \n because C was originally defined on Unix. And it's