0x15. C - Simple Shell

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Description

This team project is part of the first year curriculum of Holberton School. Simple Shell is a command line interpreter that replicates the sh program on Linux. It can take in simple commands to navigate the terminal, manipulate files, and execute programs.

What we learned:

• How a shell works and finds commands
• Creating, forking and working with processes
• Executing a program from another program
• Handling dynamic memory allocation in a large program
• Pair programming and team work
• Building a test suite to check our own code

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Compile and run

gcc -Wall -Werror -Wextra -pedantic *.c -o hsh

./hsh

Usage

• Prints a prompt and waits for a command from the user
• Creates a child process in which the command is checked
• Checks for built-ins, aliases in the PATH, and local executable programs
• The child process is replaced by the command, which accepts arguments
• When the command is done, the program returns to the parent process and prints the prompt
• The program is ready to receive a new command
• To exit: press Ctrl-D or enter "exit" (with or without a status)
• Works also in non interactive mode

Examples

$ /bin/ls
foo main.c coquille.c README.md tests croissant.c

$ pwd 
/home/vagrant/simple_shell

$ ls -l
total 60
drwxrwxr-x 7 vagrant vagrant  4096 Apr  7 01:48 foo
-rw-rw-r-- 1 vagrant vagrant   148 Apr  7 00:00 main.c
-rwxrw-r-- 1 vagrant vagrant    28 Apr  7 15:35 coquille.c

$ baguette
./hsh: No such file or directory

$ echo "cat testfile" | ./hsh
This is a test file

Files

File	Content
main.c	entry point, executing function
shell.h	function prototypes, standard libraries, structs
print_funcs.c	printing functions
print_errors.c	error printing functions
string_funcs_1.c	string-handling functions
string_funcs_2.c	string-handling functions
list_funcs_1.c	linked list handling functions
list_funcs_2.c	linked list handling functions
tokenize.c	string to tokens parsing functions
path_finder.c	functions that check the PATH for commands
builtins.c	functions dealing with the shell builtins
set_env.c	functions dealing with the setenv/unsetenv builtins
helper_funcs.c	memory and signal handling functions
convert_funcs.c	conversion between string and number functions
man_1_simple_shell	Simple Shell man page (man ./man_1_simple_shell)

Authors

Laura Roudge

Github - Twitter - LinkedIn

I am a Full-Stack Software Engineer, and I finished the foundations year at Holberton School in San Francisco, where I was also a Teaching Assistant. I currently live in Paris, France, but I am always open to opportunities to travel abroad.

I am most proficient in Python and Javascript, and am curious about learning more Node.js, and Javascript frameworks like Vue.js as I move forward.

I am mission-driven and always excited about helping others, which is why I took a Teaching Assistant role at Holberton School. I value inclusivity, equality and kindness more than anything else.

Scout Curry

Github - Twitter - LinkedIn