fgets

一起来学matlab-matlab学习笔记5 低级文件输入输出函数 觉得有用的话,欢迎一起讨论相互学习~ Follow Me 参考书籍 《matlab 程序设计与综合应用》张德丰等著 感谢张老师的书籍，让我领略到matlab的便捷 MATLABt提供了一组低级文件I/O函数，这些函数都是基于ANSI标准C库的I/O. MATLAB文件I/O函数使用与C语言子程序一样的设计模式，要读/写数据，需要执行以下步骤。 (1)使用fopen函数打开文件。fopen返回文件的标识符，标识符将被用在所有其他低级文件I/O函数中。 (2)在文件上进行以下操作： 口使用fread函数读二进制数据。 口使用fwrite函数写二进制数据。 口使用fgets/fgetl函数从文本文件中逐行读字符串。 口使用fscanf函数读格式化的ASCII数据。 口使用fprintf函数写格式化的ASCII数据。 (3)使用fclose函数关闭文件。 除了上述操作步骤，还将涉及读／写数据时，如何确定文件上读/写的位置，以及怎样改变位置。 打开文件 >>fid=fopen('fgetl.m'); tline=fgetl(fid); while ischar(tline) disp(tline); tline=fgetl(fid); end fclose(fid); 验证文件的标识符，确保能成功打开所需要的文件

首先，先稍微了解系统调用的概念： 系统调用，英文名system call，每个操作系统都在内核里有一些内建的函数库，这些函数可以用来完成一些系统系统调用把应用程序的请求传给内核，调用相应的的内核函数完成所需的处理，将处理结果返回给应用程序，如果没有系统调用和内核函数，用户将不能编写大型应用程序，及别的功能，这些函数集合起来就叫做程序接口或应用编程接口(Application Programming Interface，API)，我们要在这个系统上编写各种应用程序，就是通过这个API接口来调用系统内核里面的函数。如果没有系统调用，那么应用程序就失去内核的支持。 现在，再聊不带缓存的I/O操作： linix对IO文件的操作分为不带缓存的IO操作和标准IO操作（即带缓存），刚开始，要明确以下几点： 1：不带缓存，不是直接对磁盘文件进行读取操作,像read()和write()函数，它们都属于系统调用，只不过在用户层没有缓存，所以叫做无缓存IO,但对于内核来说，还是进行了缓存，只是用户层看不到罢了。如果这一点看不懂，请看第二点； 2：带不带缓存是相对来说的，如果你要写入数据到文件上时（就是写入磁盘上），内核先将数据写入到内核中所设的缓冲储存器，假如这个缓冲储存器的长度是100个字节，你调用系统函： ssize_t write (int fd,const void * buf,size_t

I'm having trouble with a fairly basic bit of code. I need to read each line from the file shown below, split it up into the 3 parts with strtok, and store each part into an array. The arrays for "goals" and "assists" are working perfectly, but for some reason the entire name array is filled with the last name read from the file. Input file: Redden 2 0 Berglund 5 2 Jackman 2 0 Stewart 4 0 Oshie 3 5 McDonald 2 4 Pietrangelo 2 7 Perron 2 6 Tarasenko 5 5 Relevant code: int main(int argc, char* argv){ FILE* inFile = fopen(argv[1],"r"); char ** nameArray; int * goalArray; int * assistArray; int

I started on a little toy project in C lately and have been scratching my head over the best way to mimic the strip() functionality that is part of the python string objects. Reading around for fscanf or sscanf says that the string is processed upto the first whitespace that is encountered. fgets doesn't help either as I still have newlines sticking around. I did try a strchr() to search for a whitespace and setting the returned pointer to '\0' explicitly but that doesn't seem to work. There is no standard C implementation for a strip() or trim() function. That said, here's the one included in

So basically I want to copy everything i write to stdin (including newline char) to string for hash purposes. I managed to accomplish that and made small code to represent my problem. #include <stdio.h> #include <string.h> #include <stdlib.h> #define BUFFERSIZE 10000 int main() { char *myStr = calloc(1,1); char buffer[BUFFERSIZE]; while( fgets(buffer, BUFFERSIZE , stdin) != NULL ){ myStr = realloc(myStr, strlen(myStr)+1+strlen(buffer) ); strcat( myStr, buffer ); } printf("\n%s\n",myStr); } everything works when I enter some text then press ENTER and after I call EOF. But when I start program

This is for a homework assignment to sort some given strings. I'm prompting the user for the number of strings they'd like to sort with scanf , allocating an array based on that number, and then getting the strings themselves with fgets . Everything works fine if the number of strings is hardcoded, but the addition of scanf to let the user decide screws things up. Here's the code: #include <assert.h> #include <stdio.h> #include <stdlib.h> #define LENGTH 20 // Maximum string length. int main(void) { int index, numStrings = 0; char **stringArray; printf("Input the number of strings that you'd