A shell is a command-line interface that executes commands and manages processes. This is our own POSIX compliant shell that's capable of interpreting shell commands, running external programs and builtin commands like cd, pwd, echo and more.
- Unless specified otherwise, your program must have the exact same output as
sh(/bin/sh) as well as the exact same error output. - The only difference is when you print an error, the name of the program must be equivalent to your
argv[0](See below)
Example of error with sh:
$ echo "qwerty" | /bin/sh
/bin/sh: 1: qwerty: not found
$ echo "qwerty" | /bin/../bin/sh
/bin/../bin/sh: 1: qwerty: not found
$
Same error with your program hsh:
$ echo "qwerty" | ./hsh
./hsh: 1: qwerty: not found
$ echo "qwerty" | ./././hsh
./././hsh: 1: qwerty: not found
$
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Our shell is compiled this way:
gcc -Wall -Werror -Wextra -pedantic -std=gnu89 *.c -o hsh
Our shell work like this in interactive mode:
$ ./hsh
($) /bin/ls
hsh main.c shell.c
($)
($) exit
$
But also in non-interactive mode:
$ echo "/bin/ls" | ./hsh
hsh main.c shell.c test_ls_2
$
$ cat test_ls_2
/bin/ls
/bin/ls
$
$ cat test_ls_2 | ./hsh
hsh main.c shell.c test_ls_2
hsh main.c shell.c test_ls_2
$
- Unix shell
- Thompson shell
- Ken Thompson
- Everything you need to know to start coding your own shell concept page