How to Obtain User Home Directories in Linux C Programs Without Relying on Environment Variables?

Obtaining User Home Directories in Linux

When developing C programs running on Linux, it may be necessary to retrieve the user's home directory. To accomplish this without relying on the HOME environment variable, a more reliable approach is available.

To obtain the home directory in Linux, the following steps can be taken:

1. Determine User ID:
Utilize the getuid() function to obtain the user ID of the current user.

2. Retrieve Password Entry:
Using the getpwuid() function, you can acquire the password entry associated with the obtained user ID. This entry encapsulates the home directory.

Example Code:

<code class="c++">#include <unistd.h>
#include <sys/types.h>
#include <pwd.h>

struct passwd *pw = getpwuid(getuid());

const char *homedir = pw->pw_dir;</code>

It's important to note that if your application utilizes threading, you should employ the getpwuid_r function instead for thread safety.

Root Home Directory Access:

The root home directory is typically located at /root. If your program operates under the root user, creating files or folders within this directory is acceptable. However, exercising caution and limiting such actions to essential tasks is advisable.

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