如何用C来完成通配符功能? [英] how to use C to complete a wildcard function?
问题描述
我是C的菜鸟，现在想用C来完成一个通配符功能.比如我写了一个名为myphoto的照片处理程序，我想这样使用它:myphoto ./photos/*.png，然后myphoto将处理所有目录中的png文件一一.
I am a rookie on C, and now I want to use C to complete a wildcard function. For example, I write a photo processing program named myphoto, and I want to use it like this: myphoto ./photos/*.png, and then myphoto will process all the png file in the dir one by one.
我想尽可能简单地解决这个问题，不使用正则表达式，我想出了一个想法，也许我可以使用 EXEC 函数来执行命令，但是EXEC 函数只返回 int，而不返回 char*.
I would like to solve this problem as easily as possible, without the usage of regular expression, and I came up with a idea that maybe I could use the EXEC function to execute a command, but the EXEC function only returns int, not the char*.
那么我该如何解决这个问题呢?谢谢！
So how can I solve this problem? thanks!
推荐答案
它是特定于操作系统的.我给出了 Posix 和 Linux 的观点(在 Windows 上是不同的，我不知道).
It is operating system specific. I'm giving a Posix and Linux point of view (on Windows it is different, and I don't know it).
注意，如果你正在编写程序 myprog.c 编译成 myprog 然后运行myprog photos/*.png myprog.c 中的 main 函数正在获取一个字符串数组(声明 int main(int argc, char**argv) 那么参数数组在数组 argv ....) 中有 argc 字符串.扩展由 shell 在启动 myprog 二进制可执行文件之前完成.参见 execve(2)
Notice that if you are writing the program myprog.c compiled into myprog then running
myprog photos/*.png the main function in myprog.c is getting an array of strings (declare int main(int argc, char**argv) then the array of arguments has argc strings in array argv ....). The expansion is done by the shell before starting your myprog binary executable. See execve(2)
在 Linux 和 Posix 系统上:阅读 glob(7)，你可能想使用 glob(3) 和/或 fnmatch(3) 和/或 wordexp(3).如果某些数据(例如文件中的一行)包含 photos/*.jpeg 并且您的程序想要glob"它，这些函数最有用.您不需要全局化" main 的参数，这已经由您的 shell 完成了.
On Linux and Posix systems: read glob(7), you may want to use glob(3) and/or fnmatch(3) and/or wordexp(3). These functions are useful mostly if some data (e.g. a line in a file) contains photos/*.jpeg and your program want to "glob" that. You don't need to "glob" the arguments of main, this has been done already by your shell.
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