ls2.c-------------------------------------------

/* ls2.c

* purpose list contents of directory or directories

* action if no args, use . else list files in args

* note uses stat and pwd.h and grp.h

* BUG: try ls2 /tmp

*/

#include

#include

#include

#include

void do_ls(char[]);

void dostat(char *);

void show_file_info( char *, struct stat *);

void mode_to_letters( int , char [] );

char *uid_to_name( uid_t );

char *gid_to_name( gid_t );

main(int ac, char *av[])

{

if ( ac == 1 )

do_ls( "." );

else

while ( --ac ){

printf("%s: ", *++av );

do_ls( *av );

}

}

void do_ls( char dirname[] )

/*

* list files in directory called dirname

*/

{

DIR *dir_ptr; /* the directory */

struct dirent *direntp; /* each entry */

if ( ( dir_ptr = opendir( dirname ) ) == NULL )

fprintf(stderr,"ls1: cannot open %s ", dirname);

else

{

while ( ( direntp = readdir( dir_ptr ) ) != NULL )

dostat( direntp->d_name );

closedir(dir_ptr);

}

}

void dostat( char *filename )

{

struct stat info;

if ( stat(filename, &info) == -1 ) /* cannot stat */

perror( filename ); /* say why */

else /* else show info */

show_file_info( filename, &info );

}

void show_file_info( char *filename, struct stat *info_p )

/*

* display the info about 'filename'. The info is stored in struct at *info_p

*/

{

char *uid_to_name(), *ctime(), *gid_to_name(), *filemode();

void mode_to_letters();

char modestr[11];

mode_to_letters( info_p->st_mode, modestr );

printf( "%s" , modestr );

printf( "%4d " , (int) info_p->st_nlink);

printf( "%-8s " , uid_to_name(info_p->st_uid) );

printf( "%-8s " , gid_to_name(info_p->st_gid) );

printf( "%8ld " , (long)info_p->st_size);

printf( "%.12s ", 4+ctime(&info_p->st_mtime));

printf( "%s " , filename );

}

/*

* utility functions

*/

/*

* This function takes a mode value and a char array

* and puts into the char array the file type and the

* nine letters that correspond to the bits in mode.

* NOTE: It does not code setuid, setgid, and sticky

* codes

*/

void mode_to_letters( int mode, char str[] )

{

strcpy( str, "----------" ); /* default=no perms */

if ( S_ISDIR(mode) ) str[0] = 'd'; /* directory? */

if ( S_ISCHR(mode) ) str[0] = 'c'; /* char devices */

if ( S_ISBLK(mode) ) str[0] = 'b'; /* block device */

if ( mode & S_IRUSR ) str[1] = 'r'; /* 3 bits for user */

if ( mode & S_IWUSR ) str[2] = 'w';

if ( mode & S_IXUSR ) str[3] = 'x';

if ( mode & S_IRGRP ) str[4] = 'r'; /* 3 bits for group */

if ( mode & S_IWGRP ) str[5] = 'w';

if ( mode & S_IXGRP ) str[6] = 'x';

if ( mode & S_IROTH ) str[7] = 'r'; /* 3 bits for other */

if ( mode & S_IWOTH ) str[8] = 'w';

if ( mode & S_IXOTH ) str[9] = 'x';

}

#include

char *uid_to_name( uid_t uid )

/*

* returns pointer to username associated with uid, uses getpw()

*/

{

struct passwd *getpwuid(), *pw_ptr;

static char numstr[10];

if ( ( pw_ptr = getpwuid( uid ) ) == NULL ){

sprintf(numstr,"%d", uid);

return numstr;

}

else

return pw_ptr->pw_name ;

}

#include

char *gid_to_name( gid_t gid )

/*

* returns pointer to group number gid. used getgrgid(3)

*/

{

struct group *getgrgid(), *grp_ptr;

static char numstr[10];

if ( ( grp_ptr = getgrgid(gid) ) == NULL ){

sprintf(numstr,"%d", gid);

return numstr;

}

else

return grp_ptr->gr_name;

}

Your task is to extend 1s2.c into ls3.c such that with --detail flag the program also outputs the current working directory (use getcwd function) o the total number directories in the current directory o the total number of files that are writeable by the current user he program should print out those numbers before exit. Hint You can modify do_ls0 and dostat0. For this lab, you can either use a global variable (bad practice btw), or return an int instead of void in dostat0 (a little better but is still a bad practice) or pass an int* to dostat0 fyou use global variables, remember to initialize it to 0 To know if a file is writeable by the current user (you) check the following; IF (current user is the owner of the file AND w bit is set in usr field) OR IF (current user is a member of the same group as the file AND w bit is set in grp field) OR IF (w bit is set in others field, so everyone can modify the file) Example result Current working directory: /export/home1/hessamla/codes/ number of directories: Total number of owner riteable files: 4 The new file name is ls3.c. The program must be modular, i.e. use separated functions to carry out the required functionalities. Furthermore, each function must be written in a separate c file. Header files must be used and included in the header file to define the functions. Finally, write a makefile to compile the whole project