我正在尝试在运行之前按名称在c中执行应用程序 我想知道这个名字是否合法。有没有 检查c的方法,并找出应用程序是否存在于PATH环境中?
感谢
答案 0 :(得分:2)
可能最好的方法是模仿月亮蘑菇已经提出的“哪个”命令的行为。
快速查看以下命令的输出
$ strace which ls
显示'which'只是循环遍历$ PATH条目,将它与命令名称连接起来(上例中为'ls')并在其上调用stat64。如果stat64返回不同于-1的内容(意味着该文件存在),它会中断循环。以下是测试命令的相关输出片段:
...
stat64("/home/mz/bin/ls", 0xbfa84350) = -1 ENOENT (No such file or directory)
stat64("/usr/local/sbin/ls", 0xbfa84350) = -1 ENOENT (No such file or directory)
stat64("/usr/local/bin/ls", 0xbfa84350) = -1 ENOENT (No such file or directory)
stat64("/usr/sbin/ls", 0xbfa84350) = -1 ENOENT (No such file or directory)
stat64("/usr/bin/ls", 0xbfa84350) = -1 ENOENT (No such file or directory)
stat64("/sbin/ls", 0xbfa84350) = -1 ENOENT (No such file or directory)
stat64("/bin/ls", {st_mode=S_IFREG|0755, st_size=96324, ...}) = 0
stat64("/bin/ls", {st_mode=S_IFREG|0755, st_size=96324, ...}) = 0
geteuid32() = 1000
getgid32() = 1000
...