Objective: write a program that can print the names of files in the current directory.

• Write a C program myls1 whose behavior resembles that of the system command ls. myls1 must accept the following parameters:

$ myls1 [-ars] [directory]

• If myls1 is provided with no parameters, it lists the names of all files in the current directory, one file name per line.
• directory specifies the name of a directory, in which case myls1 lists the names of files within that directory.
• -a switch forces myls1 to display the names of hidden files (whose names start with a "."). In the absence of this switch, hidden files are not listed.
• -s switch sorts the filenames in the lexicographical order.
• -r switch sorts the filenames in the reverse lexicographical order.
• Hint: consider using an array of strings to store the list of file names and then sorting it using qsort().
• Test myls1 using the files archived in this ZIP file, which contains several nested directories (named dirA, dirB, and dirA1, each with a number of short text files (named file*.txt). Use the following test cases when running myls1 from the directory at the same level with dirA and dirB:

$ myls1
$ myls1 -a
$ myls1 -s dirA
$ myls1 -a dirB
$ myls1 -r dirA/dirA1
$ myls1 dirB/dirB1

• A single C source code file with your work.
• Several screenshots (in PNG or JPG format) showing the results of executing the test cases listed above on a Linux terminal.