Write a C program, myls.c, to list files in a given directory. myls takes one optional command line argument specifying the directory path (either absolute or relative path). If the argument is absent, files in current directory will be listed. Typical output should look like: Case 1: directory argument absent Case 2: directory argument present $ myls   myfile1   myfile2   myfile3   myls $ myls .   myfile1   myfile2   myfile3   myls Remarks: 1. display file names in separate lines, one file each line. 2. exclude current directory entry (.) and parent directory entry (..) 3. error handling. Whenever a system call fails, exit program and display an error message by using perror. l Bonus:  Extend myls.c to myll.c to display more detailed information about the files listed: 1. Modification time (2%). Hint: ctime() function covert time_t to string. consult time.h functions (Chapter 26.3 at Dr. King's book). 2. File size (1%). 3. User name (1%). Hint: getpwuid() takes the uid variable in struct stat and return struct passwd which contains user name variable. Detail/example at: http://pubs.opengroup.org/onlinepubs/009695399/functions/getpwuid.html http://pubs.opengroup.org/onlinepubs/000095399/basedefs/pwd.h.html remember to include required header files to use these functions. 4. Group name (1%). Hint: getgrgid() takes the gid variable in struct stat and return struct group which contains group name variable. Detail/example at: http://pubs.opengroup.org/onlinepubs/009695399/functions/getgrgid.html http://pubs.opengroup.org/onlinepubs/009695399/basedefs/grp.h.html For more details about the struct stat definition, http://linux.die.net/man/2/stat . Typical output looks like: $ myll .   myfile1          myname           mygroup          32        Apr  3 01:12   myfile2          myname           mygroup          408      Apr  5 11:01   myfile3          myname           mygroup          12        Apr  3 23:10   myll               myname           mygroup          98        Apr  8 01:12 .

1. Write a C program, myls.c, to list files in a given directory.
myls takes one optional command line argument specifying the
directory path (either absolute or relative path). If the argument
is absent, files in current directory will be listed. Typical output
should look like:
Case 1: directory argument absent
Case 2: directory argument present
$ myls
myfile1
myfile2
myfile3
myls
$ myls .
myfile1
myfile2
myfile3
myls
Remarks:
1.
display file names in separate lines, one file each line.
2.
exclude current directory entry (.) and parent directory entry (..)
3.
error handling. Whenever a system call fails, exit program and
display an error message by using perror.

2. l
Bonus:
Extend myls.c to myll.c to display more detailed information
about the files listed:
1.
Modification time (2%). Hint:
ctime()
function covert time_t to string. consult time.h functions
(Chapter 26.3 at Dr. King's book).
2.
File size (1%).
3.
User name (1%). Hint:
getpwuid()
takes the uid variable in struct stat and return
struct passwd
which contains user name variable. Detail/example at:
http://pubs.opengroup.org/onlinepubs/009695399/functions/getp
wuid.html
http://pubs.opengroup.org/onlinepubs/000095399/basedefs/pwd.
h.html
remember to include required header files to use these
functions.
4.

3. Group name (1%). Hint:
getgrgid()
takes the gid variable in struct stat and return
struct group
which contains group name variable. Detail/example at:
http://pubs.opengroup.org/onlinepubs/009695399/functions/getg
rgid.html
http://pubs.opengroup.org/onlinepubs/009695399/basedefs/grp.h
.html
For more details about the struct stat definition,
http://linux.die.net/man/2/stat
.
Typical output looks like:
$ myll .
myfile1 myname mygroup 32 Apr 3
01:12
myfile2 myname mygroup 408 Apr 5
11:01
myfile3 myname mygroup 12 Apr 3
23:10
myll myname mygroup 98 Apr 8
01:12