本文主要是介绍测试，对大家解决编程问题具有一定的参考价值，需要的程序猿们随着小编来一起学习吧！

• HW 1
  • 1.Create a new directory called missing under /tmp;
  • 2.Look up the touch program. The man program is your friend.
  • 3.Use touch to create a new file called semester in missing.
  • 4.Write the following into that file, one line at a time:
  • 5.Try to execute the file. Understand why it doesn’t work.
  • 6.Run the command by explicitly starting the sh interpreter.
  • 7.Look up the chmod program
  • 8.Use chmod to make it possible to run the command ./semester.
  • 9.Use | and > to write the “last modified”date output by semester into a file called last-modified.txt in your home directory.

HW 1

1.Create a new directory called missing under /tmp;

mkdir /tmp/missing

检验:

2.Look up the touch program. The man program is your friend.

man touch

结果:

3.Use touch to create a new file called semester in missing.

touch /tmp/missing/semester

4.Write the following into that file, one line at a time:

echo '#!/bin/sh' > /tmp/missing/semester
echo 'curl --head --silent https://github.com/siyuanluo' >> /tmp/missing/semester

单引号字符串非转义

检验:

vim /tmp/missing/semester

5.Try to execute the file. Understand why it doesn’t work.

./semester
ls -l

结果:

users的权限是-rw, 第一组, 没有执行权限x

6.Run the command by explicitly starting the sh interpreter.

sh semester

结果:

解释: OS会通过sh命令的调用直接产生一个新的Shell进程，并将semester当作命令行参数传进去。新的Shell进程就会读取、解释并执行该脚本，而OS不关心该文件到底是什么，自然也就不要求可执行权限，只要求读权限就可以了

7.Look up the chmod program

man chmod

太长头疼, 还是这个吧: Linux chmod 命令 | 菜鸟教程 (runoob.com)

8.Use chmod to make it possible to run the command ./semester.

chmod 744 semester
./semester

给用户开权限x, 顺序是rwx, 全开就是111(2)->7

9.Use | and > to write the “last modified”date output by semester into a file called last-modified.txt in your home directory.

最后一问有点不太会... 哪个是last-modified time... output里面没找到啊

这篇关于测试的文章就介绍到这儿，希望我们推荐的文章对大家有所帮助，也希望大家多多支持为之网！