如何阅读在C中的控制台线？ [英] How to read a line from the console in C?

问题描述

什么是阅读在C控制台程序的全系列的最简单方法
输入的文本可能有一个可变长度的，我们不能对内容做任何假设。

What is the simplest way to read a full line in a C console program The text entered might have a variable length and we can't make any assumption about its content.

推荐答案

您需要动态内存管理，并使用与fgets 函数读取您的线路。然而，似乎没有办法，看看有多少个字符读取。所以，你使用龟etc：

You need dynamic memory management, and use the fgets function to read your line. However, there seems to be no way to see how many characters it read. So you use fgetc:

char * getline(void) {
    char * line = malloc(100), * linep = line;
    size_t lenmax = 100, len = lenmax;
    int c;

    if(line == NULL)
        return NULL;

    for(;;) {
        c = fgetc(stdin);
        if(c == EOF)
            break;

        if(--len == 0) {
            len = lenmax;
            char * linen = realloc(linep, lenmax *= 2);

            if(linen == NULL) {
                free(linep);
                return NULL;
            }
            line = linen + (line - linep);
            linep = linen;
        }

        if((*line++ = c) == '\n')
            break;
    }
    *line = '\0';
    return linep;
}

注意：切勿使用得到！它不会做边界检查，可以溢出您的缓冲区

Note: Never use gets ! It does not do bounds checking and can overflow your buffer

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