I want to access the user name in the Windows using C programming and use that name to create the path to the particular file like "c:\users\john\Roaming.....and so on". So for every system user name e.g "john" is different. Help me to find the user name at run time.
#include <stdio.h>
int main(void)
{
printf("%s\n", getenv("USERPROFILE")); // Print user's home directory.
return 0;
}
To get the user name instead of the home path replace USERPROFILE with USERNAME.
What you are looking for, here, is probably more SHGetKnownFolderPath. The function lets you find per-user special folders. This is preferred to querying usernames because the home folder may not have the same name as the user.
WSTR* location;
HRESULT hr = SHGetKnownFolderPath(FOLDERID_RoamingAppData, 0, NULL, &location);
if (SUCCEEDED(hr))
{
// location contains the folder path
// call CoTaskMemFree to free up the memory once you're done with it
CoTaskMemFree(location);
}
The list of so-called known folders is available here.
The function to get user name on windows is GetUserName
This answer, probably, will help you too.
you could use the following code to get the Username.
#include <stdlib.h>
void main(void)
{
//following gets the appdata folder
char szAppData[1024];
char * szBufer = 0;
szBufer = getenv ("APPDATA");
if (szBufer != NULL)
{
strcpy(szBufer , szAppData);
}
//following code gets the user name
char szOSUserName[1024];
szBufer = getenv ("USERNAME");
if (szBufer != NULL)
{
strcpy(szBufer , szOSUserName);
}
}
You can get the name of the current user with GetUserName:
#include <Windows.h>
#include <Lmcons.h>
#include <stdio.h>
int main()
{
char name[UNLEN + 1];
DWORD cch = UNLEN + 1;
if (GetUserName(name, &cch))
{
char cmd[100 + UNLEN + 1];
sprintf(cmd, "echo The username is \"%s\"", name); // Silly demo command
system(cmd);
}
return 0;
}
Use GetUserNameEx if you want the name in a specific format.
If you need to get the path to a special folder like "My Documents" or "Desktop" you should use the special folder functions like SHGetFolderPath or SHGetKnownFolderPath.
%USERNAME% will give you the username, but a better solution is to store it on %USERPROFILE%\\Desktop\\key.txt to at least make it OS-independent.
And an even better solution would be not to store private information on the users' desktops. Or anywhere.
Related
I want to access the user name in the Windows using C programming and use that name to create the path to the particular file like "c:\users\john\Roaming.....and so on". So for every system user name e.g "john" is different. Help me to find the user name at run time.
#include <stdio.h>
int main(void)
{
printf("%s\n", getenv("USERPROFILE")); // Print user's home directory.
return 0;
}
To get the user name instead of the home path replace USERPROFILE with USERNAME.
What you are looking for, here, is probably more SHGetKnownFolderPath. The function lets you find per-user special folders. This is preferred to querying usernames because the home folder may not have the same name as the user.
WSTR* location;
HRESULT hr = SHGetKnownFolderPath(FOLDERID_RoamingAppData, 0, NULL, &location);
if (SUCCEEDED(hr))
{
// location contains the folder path
// call CoTaskMemFree to free up the memory once you're done with it
CoTaskMemFree(location);
}
The list of so-called known folders is available here.
The function to get user name on windows is GetUserName
This answer, probably, will help you too.
you could use the following code to get the Username.
#include <stdlib.h>
void main(void)
{
//following gets the appdata folder
char szAppData[1024];
char * szBufer = 0;
szBufer = getenv ("APPDATA");
if (szBufer != NULL)
{
strcpy(szBufer , szAppData);
}
//following code gets the user name
char szOSUserName[1024];
szBufer = getenv ("USERNAME");
if (szBufer != NULL)
{
strcpy(szBufer , szOSUserName);
}
}
You can get the name of the current user with GetUserName:
#include <Windows.h>
#include <Lmcons.h>
#include <stdio.h>
int main()
{
char name[UNLEN + 1];
DWORD cch = UNLEN + 1;
if (GetUserName(name, &cch))
{
char cmd[100 + UNLEN + 1];
sprintf(cmd, "echo The username is \"%s\"", name); // Silly demo command
system(cmd);
}
return 0;
}
Use GetUserNameEx if you want the name in a specific format.
If you need to get the path to a special folder like "My Documents" or "Desktop" you should use the special folder functions like SHGetFolderPath or SHGetKnownFolderPath.
%USERNAME% will give you the username, but a better solution is to store it on %USERPROFILE%\\Desktop\\key.txt to at least make it OS-independent.
And an even better solution would be not to store private information on the users' desktops. Or anywhere.
How can I get file path to Desktop directory as a string on macOS.
I need it to be done in pure C or with some C-level framework.
If you insist on using only C (why?), then your only choice is to use deprecated APIs:
#include <limits.h>
#include <CoreServices/CoreServices.h>
...
FSRef fsref;
UInt8 path[PATH_MAX];
if (FSFindFolder(kUserDomain, kDesktopFolderType, kDontCreateFolder, &fsref) == noErr &&
FSRefMakePath(&fsref, path, sizeof(path)) == noErr)
{
// Make use of path
}
If you need a CFURL rather than a path, you can use CFURLCreateFromFSRef() rather than FSRefMakePath().
Actually, while researching this, I found an API I hadn't known about. Apparently, you can use this, which apparently comes from Cocoa but uses only C types:
#include <limits.h>
#include <NSSystemDirectories.h>
char path[PATH_MAX];
NSSearchPathEnumerationState state = NSStartSearchPathEnumeration(NSDesktopDirectory, NSUserDomainMask);
while (state = NSGetNextSearchPathEnumeration(state, path))
{
// Handle path
}
The form of the API is that it may return multiple results (one on each iteration of the loop), but you should get only one for the specific use here. In that case, you can change the while to and if.
Note that, with this API, returned paths for directories in the user domain may use "~" rather than the absolute path to the user's home directory. You'll have to resolve that yourself.
Here's a short function, which works on more Unix based systems than just macOS and returns the current user's desktop folder:
#include <limits.h>
#include <stdlib.h>
/**
* Returns the path to the current user's desktop.
*/
char *path2desktop(void) {
static char real_public_path[PATH_MAX + 1] = {0};
if (real_public_path[0])
return real_public_path;
strcpy(real_public_path, getenv("HOME"));
memcpy(real_public_path + strlen(real_public_path), "/Desktop", 8);
return real_public_path;
}
The path will only be computed once.
If the function is called more than once, the old result will be returned (not thread-safe, unless the first call was protected).
I ended with usage of Objective-C in such way:
//
// main.m
// search_path_for_dir
//
// Created by Michal Ziobro on 23/09/2016.
// Copyright © 2016 Michal Ziobro. All rights reserved.
//
#import <Foundation/Foundation.h>
int main(int argc, const char * argv[]) {
if(argc != 3)
return 1;
#autoreleasepool {
NSArray *paths = NSSearchPathForDirectoriesInDomains(atoi(argv[1]), atoi(argv[2]), YES);
NSString *path = [paths objectAtIndex:0];
[path writeToFile:#"/dev/stdout" atomically:NO encoding:NSUTF8StringEncoding error:nil];
}
return 0;
}
And than from command line I can execute this program in that way:
./search_path_for_dir 12 1
12 - NSDesktopDirectory
1 - NSUserDomainMask
I am using script in C that executes this program from command line and retrieves its output.
Here's C example calling this mini Cocoa App:
CFStringRef FSGetFilePath(int directory, int domainMask) {
CFStringRef scheme = CFSTR("file:///");
CFStringRef absolutePath = FSGetAbsolutePath(directory, domainMask);
CFMutableStringRef filePath = CFStringCreateMutable(NULL, 0);
if (filePath) {
CFStringAppend(filePath, scheme);
CFStringAppend(filePath, absolutePath);
}
CFRelease(scheme);
CFRelease(absolutePath);
return filePath;
}
CFStringRef FSGetAbsolutePath(int directory, int domainMask) {
char path_cmd[BUF_SIZE];
sprintf(path_cmd, "./tools/search_path_for_dir %d %d", directory, domainMask);
char *path = exec_cmd(path_cmd);
return CFStringCreateWithCString(kCFAllocatorDefault, path, kCFStringEncodingUTF8);
}
I have researched a lot on this topic but could not get anything substantial.
By normalize/canonicalize I mean to remove all the "..", ".", multiple slashes etc from a file path and get a simple absolute path.
e.g.
"/rootdir/dir1/dir2/dir3/../././././dir4//////////" to
"/rootdir/dir1/dir2/dir4"
On windows I have GetFullPathName() and I can get the canonical filepath name, but for Linux I cannot find any such API which can do the same work for me,
realpath() is there, but even realpath() needs the filepath to be present on the file system to be able to output normalized path, e.g. if the path /rootdir/dir1/dir2/dir4 is not on file system - realpath() will throw error on the above specified complex filepath input.
Is there any way by which one could get the normalized file path even if it is not existing on the file system?
realpath(3) does not resolve missing filenames.
But GNU core utilities (https://www.gnu.org/software/coreutils/) have a program realpath(1) which is similar to realpath(3) function, but have option:
-m, --canonicalize-missing no components of the path need exist
And your task can be done by canonicalize_filename_mode() function from file lib/canonicalize.c of the coreutils source.
canonicalize_filename_mode() from Gnulib is a great option but cannot be used in commercial software (GPL License)
We use the following implementation that depends on cwalk library:
#define _GNU_SOURCE
#include <unistd.h>
#include <stdlib.h>
#include "cwalk.h"
/* extended version of canonicalize_file_name(3) that can handle non existing paths*/
static char *canonicalize_file_name_missing(const char *path) {
char *resolved_path = canonicalize_file_name(path);
if (resolved_path != NULL) {
return resolved_path;
}
/* handle missing files*/
char *cwd = get_current_dir_name();
if (cwd == NULL) {
/* cannot detect current working directory */
return NULL;
}
size_t resolved_path_len = cwk_path_get_absolute(cwd, path, NULL, 0);
if (resolved_path_len == 0) {
return NULL;
}
resolved_path = malloc(resolved_path_len + 1);
cwk_path_get_absolute(cwd, path, resolved_path, resolved_path_len + 1);
free(cwd);
return resolved_path;
}
How can I get the current users sign in name in Windows?
What I have figured out is the function
char* user_name;
user_name=getenv("USERNAME");
but the problem is that it gives
admin
but when I sign in to Windows, my user name is "Sudip" and not "admin".
You can use GetUserName
#include <windows.h>
#include <Lmcons.h>
char username[UNLEN+1];
DWORD username_len = UNLEN+1;
GetUserName(username, &username_len);
You can use GetUserNameEx to get your display name instead of the actual user name. The EXTENDED_NAME_FORMAT enumeration has a NameDisplay entry that should do what you want.
I have a function that is used to check a list of user either that user is logged in or not.(Roughly say, the user have an active connection to the server).
This is the code:
static int is_login(char *user)
{
int found = 0;
struct utmpx *u;
setutxent();
while ((u = getutxent())) {
if ((strcmp(u->ut_user,user)==0) && (u->ut_type ==USER_PROCESS)) {
found = 1;
break;
} else {
found =0;
}
}
endutxent();
return found;
}
Dont get this wrong. This code work fine. The only issue is when /var/run/utmp permission are not set as readable. eg: chmod /var/run/utmp 600.. Even worse if the server doesnt have utmp. Instead use a utmps. Is there any other function that can do the same thing as getutxent()? So far what I only found is getpwuid(getuid()) and getlogin() which only return the user that logged in on the controlling terminal.
This is what I have tested
#include <unistd.h>
#include <stdio.h>
#include <pwd.h>
int main()
{
char *name;
struct passwd *pass;
while(pass = getpwuid(getuid())) //I've tested also with getlogin(), but without the struct ofcourse.
{
name = pass->pw_name;
printf("user = %s\n",name);
}
return 0;
}
While running this test program, I logged in with 2 more different user into that system, but those 2 user's name doesnt appear on the screen.
I'm working on the project with the same functionality as yours (e.g. login events monitoring), but I have to rely onto the /var/log/secure file. It provides much more information for me. May be you should take it into account.