Single pipe `|`

[superxcgm]

Epic

Process

Description

For good user experience, user can add chain commands using pipeline

AC

Given: User type some_command (For example: echo ab) When: User hit Then: Print ab on console.

Given: User type some_command | another_command (For example:ls -l | grep 'hello') When: User hit Then: Should use output of first command as input of second command.

Out of Scope

Support of multi pipe, like command1 | command2 | command3

[lq1149622825]

Technical knowledge used

1. fork() multi-process programming
2. pipe principle
3. Redirection principle

   tsaking

4. Split the command to get the set of command_parse_result;
5. Get the set of command_pase_result, and get the part that needs "|" for processing according to the size
6. Create two child processes. Colleagues process two commands, and write the output of the first command to the pipeline at the same time, and the second line of commands is processed from the read data
7. refactor

[lq1149622825]

9月22日

redirection bug

• such as user input "> a.txt || < a.txt" , program error

single Pipe line progress

• Steps 1 to 3 are basically completed, there is a problem with pipeline redirection, which needs to be resolved（solved today）

Unresolved problem

• build_in alias have bug,such as user input "alias ll = 'ls -lh'",or input "alias",program have no output

[lq1149622825]

9月23日

redirection bug

• such as user input "> a.txt || < a.txt" , program error
• such as user input "alias" , program having nothing print

single Pipe line progress

• solve the build_in command pipe line(build_in alias have bug,such as user input "alias ll = 'ls -lh'",or input "alias",program have no output)

mutil Pipe line progress

• do the tasking with mutil pipe card;

[superxcgm]

QA

Given: User type some_command (For example: echo ab) When: User hit Then: ✅Print ab on console.

Given: User type some_command | another_command (For example:ls -l | grep 'hello' ) When: User hit Then: ✅Should use output of first command as input of second command.