Assumptions

Spec 1

Prompt format: username@system-name:directory recent-foreground-process:time $

Spec 2

Only tabs and spaces are considered whitespace characters.

Spec 3

• When given multiple arguments to hop, it sequentially moves to those directories until an erroneous path is given.

Spec 4

• A file is considered hidden if and only if its name starts with .
• reveal -l will also print the destination of symbolic links, like bash's ls -l.
• This code works for an arbitrary number of directory entries (as it uses dynamic memory allocation).
• Using the - argument as a directory will raise an Invalid path error if no previous working directory exists.

Spec 5

• Erroneous commands are also logged.
• The command corresponding to the index in log execute <index> also gets logged while running log exeute.
• log execute n executes the nth most recent command.
• log displays logged commands, newest at the bottom.
• The exit command is logged.

Spec 6

• PIDs range from 1 to 9999999.
• On running an erroneous system command in the background, it will first show the error then say that the erroneous process exited abnormally, as it should.

Spec 7

• A process is considered a background process if its controlling terminal is 0. Although this is not always the case, it is a reasonable assumption.
• To obtain all the information about some processes, like executable paths, it is required to run the shell in sudo, otherwise it will raise a Permission denied error.
• The Virtual Memory field shows the number of bytes of memory that the process is using.

Spec 8

• Executables won't be searched for, with the -e flag.

Spec 9

• Dynamic aliasing is supported.
• Aliases should be set in the format alias xx = yy. Note that spacing matters. Everything must be space-separated. xx must be a single word, yy can be multiple.
• Typing alias will show a list of all aliases made so far.
• .myshrc works like a typical run-commands file for any shell, it will run all the commands present in it on startup.

Spec 10, 11, 12

• Will work as expected for valid commands, but for commands involving <, > and >>, they must be separated by spaces.

Spec 13

• Running processes are printed in ascending order of their PIDs.

Spec 14

• None.

Spec 15

• None.

Spec 16

• None.

Spec 17

• None.