/* Copyright (C) 1999, 2000, 2002, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */ #include <errno.h>
#include <unistd.h> #include <sysdep.h>
#include <alloca.h>
#include <sys/syscall.h>
#include <bp-checks.h>
#include <stdio.h> int
__execve (file, argv, envp)
const char *file;
char *const argv[];
char *const envp[];
{
#if __BOUNDED_POINTERS__
{
printf("__BOUNDED_POINTERS__,-powered by elliot4718");
char *const *v;
int i;
char *__unbounded *__unbounded ubp_argv;
char *__unbounded *__unbounded ubp_envp;
char *__unbounded *__unbounded ubp_v; for (v = argv; *v; v++)
;
i = v - argv + ;
ubp_argv = (char *__unbounded *__unbounded) alloca (sizeof (*ubp_argv) * i);
for (v = argv, ubp_v = ubp_argv; --i; v++, ubp_v++)
*ubp_v = CHECK_STRING (*v);
*ubp_v = ; for (v = envp; *v; v++)
;
i = v - envp + ;
ubp_envp = (char *__unbounded *__unbounded) alloca (sizeof (*ubp_envp) * i);
for (v = envp, ubp_v = ubp_envp; --i; v++, ubp_v++)
*ubp_v = CHECK_STRING (*v);
*ubp_v = ; return INLINE_SYSCALL (execve, , CHECK_STRING (file), ubp_argv, ubp_envp);
}
#else
printf("__NONONONONONONO__,-powered by elliot4718"); return INLINE_SYSCALL (execve, , file, argv, envp);
#endif
}
weak_alias (__execve, execve)
/* Copyright (C) 1991,92, 1995-99, 2002, 2004, 2005, 2007, 2009
Free Software Foundation, Inc.
This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */ #include <alloca.h>
#include <unistd.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <paths.h> /* The file is accessible but it is not an executable file. Invoke
the shell to interpret it as a script. */
static void
internal_function
scripts_argv (const char *file, char *const argv[], int argc, char **new_argv)
{
/* Construct an argument list for the shell. */
new_argv[] = (char *) _PATH_BSHELL;
new_argv[] = (char *) file;
while (argc > )
{
new_argv[argc] = argv[argc - ];
--argc;
}
} /* Execute FILE, searching in the `PATH' environment variable if it contains
no slashes, with arguments ARGV and environment from ENVP. */
int
__execvpe (file, argv, envp)
const char *file;
char *const argv[];
char *const envp[];
{
if (*file == '\0')
{
/* We check the simple case first. */
__set_errno (ENOENT);
return -;
} if (strchr (file, '/') != NULL)
{
/* Don't search when it contains a slash. */
__execve (file, argv, envp); if (errno == ENOEXEC)
{
/* Count the arguments. */
int argc = ;
while (argv[argc++])
;
size_t len = (argc + ) * sizeof (char *);
char **script_argv;
void *ptr = NULL;
if (__libc_use_alloca (len))
script_argv = alloca (len);
else
script_argv = ptr = malloc (len); if (script_argv != NULL)
{
scripts_argv (file, argv, argc, script_argv);
__execve (script_argv[], script_argv, envp); free (ptr);
}
}
}
else
{
size_t pathlen;
size_t alloclen = ;
char *path = getenv ("PATH");
if (path == NULL)
{
pathlen = confstr (_CS_PATH, (char *) NULL, );
alloclen = pathlen + ;
}
else
pathlen = strlen (path); size_t len = strlen (file) + ;
alloclen += pathlen + len + ; char *name;
char *path_malloc = NULL;
if (__libc_use_alloca (alloclen))
name = alloca (alloclen);
else
{
path_malloc = name = malloc (alloclen);
if (name == NULL)
return -;
} if (path == NULL)
{
/* There is no `PATH' in the environment.
The default search path is the current directory
followed by the path `confstr' returns for `_CS_PATH'. */
path = name + pathlen + len + ;
path[] = ':';
(void) confstr (_CS_PATH, path + , pathlen);
} /* Copy the file name at the top. */
name = (char *) memcpy (name + pathlen + , file, len);
/* And add the slash. */
*--name = '/'; char **script_argv = NULL;
void *script_argv_malloc = NULL;
bool got_eacces = false;
char *p = path;
do
{
char *startp; path = p;
p = __strchrnul (path, ':'); if (p == path)
/* Two adjacent colons, or a colon at the beginning or the end
of `PATH' means to search the current directory. */
startp = name + ;
else
startp = (char *) memcpy (name - (p - path), path, p - path); /* Try to execute this name. If it works, execve will not return. */
__execve (startp, argv, envp); if (errno == ENOEXEC)
{
if (script_argv == NULL)
{
/* Count the arguments. */
int argc = ;
while (argv[argc++])
;
size_t arglen = (argc + ) * sizeof (char *);
if (__libc_use_alloca (alloclen + arglen))
script_argv = alloca (arglen);
else
script_argv = script_argv_malloc = malloc (arglen);
if (script_argv == NULL)
{
/* A possible EACCES error is not as important as
the ENOMEM. */
got_eacces = false;
break;
}
scripts_argv (startp, argv, argc, script_argv);
} __execve (script_argv[], script_argv, envp);
} switch (errno)
{
case EACCES:
/* Record the we got a `Permission denied' error. If we end
up finding no executable we can use, we want to diagnose
that we did find one but were denied access. */
got_eacces = true;
case ENOENT:
case ESTALE:
case ENOTDIR:
/* Those errors indicate the file is missing or not executable
by us, in which case we want to just try the next path
directory. */
case ENODEV:
case ETIMEDOUT:
/* Some strange filesystems like AFS return even
stranger error numbers. They cannot reasonably mean
anything else so ignore those, too. */
break; default:
/* Some other error means we found an executable file, but
something went wrong executing it; return the error to our
caller. */
return -;
}
}
while (*p++ != '\0'); /* We tried every element and none of them worked. */
if (got_eacces)
/* At least one failure was due to permissions, so report that
error. */
__set_errno (EACCES); free (script_argv_malloc);
free (path_malloc);
} /* Return the error from the last attempt (probably ENOENT). */
return -;
}
weak_alias (__execvpe, execvpe)

在execve中为了寻找argv对字符串的解析,直接不给力。最后找到了execvp的代码,原来就是这么简单。。。。

execve(file, argv, env)参数argv获取字符串个数的更多相关文章

  1. golang 中获取字符串个数

    golang 中获取字符串个数 在 golang 中不能直接用 len 函数来统计字符串长度,查看了下源码发现字符串是以 UTF-8 为格式存储的,说明 len 函数是取得包含 byte 的个数 // ...

  2. C关键字typedef及argc,argv,env参数含义

    C关键字typedef--为C中各种数据类型定义别名. 在此插一点C知识 int main(int argc,const char *argv[],const char *envp[])主函数的红色部 ...

  3. (转)Shell中获取字符串长度的七种方法

    Shell中获取字符串长度的七种方法 原文:http://blog.csdn.net/jerry_1126/article/details/51835119 求字符串操作在shell脚本中很常用,下面 ...

  4. Shell获取字符串长度的多种方法总结

    摘自:https://www.jb51.net/article/121290.htm 前言 我们在日常工作中,对于求字符串操作在shell脚本中很常用,实现的方法有很多种,下面就来给大家归纳.汇总了求 ...

  5. python(38):sys.argv,sys.argv.pop(),获取用户的外部输入,非指定

    见下面的例子(一): # /usr/bin/env python # coding=utf8 import os import requests import sys if __name__ == & ...

  6. shell脚本中,将所有的参数值否赋给一个变量或者说将所有的参数合成一个字符串,获取所有参数

    需求描述: 在写脚本的过程中,遇到这样的一个需求,将脚本执行过程中,传递给 脚本的所有的参数,都赋值给一个变量然后在对这个变量进行处理. 测试过程: 通过以下的脚本将所有传递给脚本的变量都赋值一个变量 ...

  7. nodejs中命令行中参数的获取和解析

    首先,假设有如下的命令行 node  abc.js arg1 arg2 arg3,现在想在abc.js中获取后面的参数arg1.arg2.arg3… var args = process.argv.s ...

  8. SpringMVC请求参数的获取方式

    一.GET请求参数获取 1. 通过HttpServletRequest获取参数 2. 直接方法参数获取 3. RequestParam注解方式获取请求参数 4. Bean方式获取参数 5. Model ...

  9. [No0000A4]DOS命令(cmd)批处理:替换字符串、截取字符串、扩充字符串、获取字符串长度

    1.替换字符串,即将某一字符串中的特定字符或字符串替换为给定的字符串.举例说明其功能:========================================= @echo off set a ...

随机推荐

  1. Final Cut Pro X效果插件开发总结

    一.介绍 最近公司需要针对Final Cut Pro(FCP)开发一款效果插件,用于对公司自己开发的视频格式进行后期处理.Final Cut Pro是苹果公司推出的一款视频剪辑软件,因此需要在OSX平 ...

  2. 常见的Web实时消息交互方式和SignalR

    标签: WebSocket SignalR 前言 1. Web消息交互技术 1.1 常见技术 1.2 WebSocket介绍 1.3 WebSocket示例 2. Signal 2.1 SignalR ...

  3. java.lang.Exception: Could not determine the type of file "smb://zhangsan:123456@10.77.44.222/o/mmfiles_2016/40094/25556/2130.avi".

    1. 使用smb协议上传文件 报上述错误 2. 解决方法 开启administrator超级管理员 smb地址改为smb://administrator:123456@10.10.10.10/o/.. ...

  4. python之redis和memcache操作

    Redis 教程 Redis是一个开源(BSD许可),内存存储的数据结构服务器,可用作数据库,高速缓存和消息队列代理.Redis 是完全开源免费的,遵守BSD协议,是一个高性能的key-value数据 ...

  5. Hadoop2.6.0安装 — 集群

    文 / vincentzh 原文连接:http://www.cnblogs.com/vincentzh/p/6034187.html 这里写点 Hadoop2.6.0集群的安装和简单配置,一方面是为自 ...

  6. JavaWeb之CSS详解

    CSS的简介 1.CSS概述及作用 CSS:Cascading Style Sheets)是层叠样式表用来定义网页的显示效果.可以解决html代码对样式定义的重复,提高了后期样式代码的可维护性,并增强 ...

  7. ALV TREE中双击触发PAI事件的方法

    用事件类实现双击事件,实例化后使用set handler注册到ALV对象.斜体部分为事件方法的具体实现. 代码如下 CLASS lcl_tree_event_receiver DEFINITION. ...

  8. SE16N使用方案总结

    SAP中直接修改表.视图的Tcode有SE16N和SM30. 另外,在EHP5版本及其更高的版本中,激活编辑功能是不被允许的,不过程序中是通过一个判断语句来限制的,可以通过将相关的判断值判断前加断点, ...

  9. Android中的AlertDialog使用示例三(单向选择确定对话框)

    在Android开发中,我们经常会需要在Android界面上弹出一些对话框,比如询问用户或者让用户选择.这些功能我们叫它Android Dialog对话框,AlertDialog实现方法为建造者模式. ...

  10. Android开发学习——基础学习

    在微信公众号上,发现一个自学android的一个文章,觉得不错.对其进行小小总结,整理给大家. 1. 基础UI学习 Button/TextView/EditText/CheckBox/ImageVie ...