Help Please - Printing the path for links

**lewiso** · 03-04-2008

Hi I have written this directory listing. The problem I have is that i am trying to print the path for the links.

e.g. like this: "Link to filedata -> /home/user/files/filedata".

All its printing at the moment is "Link to filedata ->".

I dont know much about C programming but I know this code works fine as I took it directly from another application where it works fine. Its driving me mad. Please could someone point out what i need to change to make it work.

**Elysia** · 03-04-2008

This is Linux, is it not? And it's not C#, it's C.
Here's a properly indented version:

Code:

#include <dirent.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <pwd.h>
#include <grp.h>
#include <time.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <unistd.h>

int lsdetails(struct stat *statbuff);
int outputfiletype(mode_t filetype);
int recls(char *path);
int printperms(mode_t mode);
char monthprint[4];
int main(int argc, char **argv){

	printf("\n");
	if (argc<2)
	{
		recls(".");
		return(0);
	}
	recls(argv[1]);
}

int recls(char *path)	{  		/* function expects char as argument 			 */
	DIR *dir;			/* Declare DIR function, create pointer "*dir"	  	 */			
	struct dirent *dirslot;		/* Declare struct "dirent", create "*dirslot"		 */
	struct stat statbuff;		/* Declare struct "stat", create "statbuff"		 */
	int islnk = 0;
	char lbuffer[256];
	char *name;

	chdir(path);
	dir=opendir(".");		
	if (dir == NULL) {
		printf("\nNo such directory\n");
		return(1);
	}
	while (1) {		
		dirslot=readdir(dir);



		if (dirslot==NULL) break;//note change	

		lstat(dirslot->d_name, &statbuff); 

		if (strcmp(dirslot->d_name, ".")==0) continue;  
		if (strcmp(dirslot->d_name, "..")==0) continue;   

		if (S_ISLNK(statbuff.st_mode))  {
			lsdetails(&statbuff);
			printf("\033[36m&#37;s\033[m", dirslot->d_name);
		}


		if ((statbuff.st_mode & S_IFMT) == S_IFLNK) {
			islnk = 1;
			memset(lbuffer, 0, 256);
			readlink(name, lbuffer, 256);
			printf("%s %s \n", (islnk) ? " -> " : "", (islnk) ? lbuffer : " ");
		}

		if (S_ISREG(statbuff.st_mode))  {
			lsdetails(&statbuff);
			printf("\033[0m%s\033[m\n", dirslot->d_name);
		}

		if (S_ISDIR(statbuff.st_mode))  {
			lsdetails(&statbuff);
			printf("\033[34;42m%s\033[m\n", dirslot->d_name);
		}

		if (S_ISCHR(statbuff.st_mode))  {
			lsdetails(&statbuff);
			printf("\033[01;32m%s\033[m\n", dirslot->d_name);
		}

		/*if (dirslot->d_type == DT_UNKNOWN) {
		lsdetails(&statbuff);
		printf("\033[0m%s\033[m\n", dirslot->d_name);	
		}
		if (dirslot->d_type == DT_FIFO) {
		lsdetails(&statbuff);
		printf("\033[0m%s\033[m\n", dirslot->d_name);	
		}
		if (dirslot->d_type == DT_CHR) {
		lsdetails(&statbuff);
		printf("\033[01;33m%s\033[m\n", dirslot->d_name);	
		}

		if (dirslot->d_type == DT_BLK) {
		lsdetails(&statbuff);
		printf("\033[0m%s\033[m\n", dirslot->d_name);	
		}

		if (dirslot->d_type == DT_WHT) {
		lsdetails(&statbuff);
		printf("\033[0m%s\033[m\n", dirslot->d_name);	
		}*/


	}


	rewinddir(dir);					   /* rewind the directory stream, start from the top */	
	while (1) {
		dirslot=readdir(dir);
		if (dirslot==NULL) return(1);
		if (strcmp(dirslot->d_name, ".")==0) continue;     /* if d_name equals ".", skip rest of loop */
		if (strcmp(dirslot->d_name, "..")==0) continue;    /* if d_name equals "..", skip rest of loop */

		lstat(dirslot->d_name, &statbuff);

		if (S_ISDIR(statbuff.st_mode))  {
			printf("\n./\033[01;34m%s\033[m\n", dirslot->d_name);


			if (chdir(dirslot->d_name)==-1) {
				perror("Error: chdir");
				return;}

			recls(".");
			chdir("..");

		}        	
	}
}

int printperms(mode_t modebit)	{
	char perms[10]; 
	int i;
	for (i=0;i<9; i++) perms[i]='-';
	perms[9] = 0;

	if (((modebit) & S_IRUSR)!=0) perms[0] = 'r'; 
	if (((modebit) & S_IWUSR)!=0) perms[1] = 'w';  //User Perms
	if (((modebit) & S_IXUSR)!=0) perms[2] = 'x';
	if (((modebit) & S_IRGRP)!=0) perms[3] = 'r'; 
	if (((modebit) & S_IWGRP)!=0) perms[4] = 'w';   //Group Perms
	if (((modebit) & S_IXGRP)!=0) perms[5] = 'x';
	if (((modebit) & S_IROTH)!=0) perms[6] = 'r';
	if (((modebit) & S_IWOTH)!=0) perms[7] = 'w';  //Others
	if (((modebit) & S_IXOTH)!=0) perms[8] = 'x';	
	//else fprintf(stderr,"FAIL: Cannot determine file permission mask");
	printf("%s ", perms);
	return(0);		
}

int printfiletype(mode_t filetype)	{

	char * mode;

	if(S_ISREG(filetype)) mode = "-";
	else if(S_ISDIR(filetype)) mode = "d";
	else if(S_ISCHR(filetype)) mode = "c";
	else if(S_ISBLK(filetype)) mode = "b";
	else if(S_ISFIFO(filetype)) mode = "f";
	else if(S_ISSOCK(filetype)) mode = "s";
	else if(S_ISLNK(filetype)) mode = "l";
	else fprintf(stderr,"FAIL: Cannot determine file mode");		
	printf ("%s", mode);
	return(0);		
}



int lsdetails(struct stat *statbuff) {

	struct passwd *pw;
	struct group *gp;
	struct tm *tm_ptr;



	tm_ptr = gmtime(&statbuff->st_ctime);

	if(tm_ptr-> tm_mon+ 1 == 1) strcpy(monthprint,"Jan");
	else if(tm_ptr-> tm_mon+ 1 == 2) strcpy(monthprint,"Feb");
	else if(tm_ptr-> tm_mon+ 1 == 3) strcpy(monthprint,"Mar");
	else if(tm_ptr-> tm_mon+ 1 == 4) strcpy(monthprint,"Apr");		
	else if(tm_ptr-> tm_mon+ 1 == 5) strcpy(monthprint,"May");
	else if(tm_ptr-> tm_mon+ 1 == 6) strcpy(monthprint,"Jun");
	else if(tm_ptr-> tm_mon+ 1 == 7) strcpy(monthprint,"Jul");
	else if(tm_ptr-> tm_mon+ 1 == 8) strcpy(monthprint,"Aug");
	else if(tm_ptr-> tm_mon+ 1 == 9) strcpy(monthprint,"Sep");
	else if(tm_ptr-> tm_mon+ 1 == 10) strcpy(monthprint,"Oct");		
	else if(tm_ptr-> tm_mon+ 1 == 11) strcpy(monthprint,"Nov");
	else if(tm_ptr-> tm_mon+ 1 == 12) strcpy(monthprint,"Dec");
	else fprintf(stderr, "FAIL: Cannot determine month");

	printfiletype(statbuff->st_mode);
	printperms(statbuff->st_mode);
	printf( "%d ", statbuff->st_nlink);

	if ((pw = getpwuid(statbuff->st_uid)) != NULL) printf("%s  ", pw->pw_name);	 
	else fprintf(stderr,"UID ERROR" );

	if ((gp = getgrgid(statbuff->st_gid)) != NULL) printf("%s  ", gp->gr_name);
	else fprintf(stderr,"The User is not associated with any group");

	printf( "%-4d ", statbuff->st_size);
	printf( "Inode: %-4d ", statbuff->st_ino);
	printf( "%d-%s-%02d %d:%d  ",tm_ptr->tm_year+1900, monthprint, tm_ptr-> tm_mday, tm_ptr-> tm_hour, tm_ptr-> tm_min);

	return 0;
}

Thank goodness for Visual Studio.

**lewiso** · 03-04-2008

Yes this is Linux, and yes this is C not C# (typo).

Thanks for the indented version. Any idea why the link paths are not printing?

**Elysia** · 03-04-2008

I'm sorry, but I don't know Linux...

**vart** · 03-04-2008

Code:

-*- mode: compilation; default-directory: "~/test3/" -*-
Compilation started at Tue Mar  4 14:57:13

make -k 
icc -o test3.o -c -g -Wall test3.c 
test3.c(15): warning #1419: external declaration in primary source file
  int lsdetails(struct stat *statbuff);
      ^

test3.c(16): warning #1419: external declaration in primary source file
  int outputfiletype(mode_t filetype);
      ^

test3.c(17): warning #1419: external declaration in primary source file
  int recls(char *path);
      ^

test3.c(18): warning #1419: external declaration in primary source file
  int printperms(mode_t mode);
      ^

test3.c(29): remark #1011: missing return statement at end of non-void function "main"
  }
  ^

test3.c(50): warning #991: //-style comments are nonstandard
  		if (dirslot==NULL) break;//note change	
  		                         ^

test3.c(52): warning #266: function "lstat" declared implicitly
  		lstat(dirslot->d_name, &statbuff); 
  		^

test3.c(63): error: identifier "S_IFMT" is undefined
  		if ((statbuff.st_mode & S_IFMT) == S_IFLNK) {
  		                        ^

test3.c(63): error: identifier "S_IFLNK" is undefined
  		if ((statbuff.st_mode & S_IFMT) == S_IFLNK) {
  		                                   ^

test3.c(66): warning #266: function "readlink" declared implicitly
  			readlink(name, lbuffer, 256);
  			^

test3.c(119): warning #266: function "lstat" declared implicitly
  		lstat(dirslot->d_name, &statbuff);
  		^

test3.c(127): warning #117: non-void function "recls" should return a value
  				return;}
  				      ^

test3.c(156): warning #1418: external function definition with no prior declaration
  int printfiletype(mode_t filetype)	{
      ^

test3.c(165): warning #266: function "S_ISSOCK" declared implicitly
  	else if(S_ISSOCK(filetype)) mode = "s";
  	        ^

test3.c(200): warning #181: argument is incompatible with corresponding format string conversion
  	printf( "&#37;d ", statbuff->st_nlink);
  	               ^

test3.c(208): warning #181: argument is incompatible with corresponding format string conversion
  	printf( "%-4d ", statbuff->st_size);
  	                 ^

test3.c(209): warning #181: argument is incompatible with corresponding format string conversion
  	printf( "Inode: %-4d ", statbuff->st_ino);
  	                        ^

compilation aborted for test3.c (code 2)
make: *** [test3.o] Error 2
make: Target `all' not remade because of errors.

Compilation exited abnormally with code 2 at Tue Mar  4 14:57:13

I see a lot of warnings - some seems to be very dangerous - you may want to start with fixing them

**Dave_Sinkula** · 03-04-2008

<<moved to Linux and duplicate thread deleted>>

**lewiso** · 03-04-2008

I'm not getting any warnings when compiling. Plus the program runs fine, just not printing the links.

**lewiso** · 03-04-2008

Any ideas what is wrong with it?

**matsp** · 03-04-2008

I have no idea what is actually wrong, but this is the bit of code that supposedly reads the link:

Code:

		if ((statbuff.st_mode & S_IFMT) == S_IFLNK) {
			islnk = 1;
			memset(lbuffer, 0, 256);
			readlink(name, lbuffer, 256);
			printf("%s %s \n", (islnk) ? " -> " : "", (islnk) ? lbuffer : " ");
		}

--
Mats

**lewiso** · 03-04-2008

got it working in the end.

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