Packages(Linux): Auto detect the DBPath directory for pacman on archlinux

[It-is-Sean]

Summary

Replace the original hardcoded pacman database path. Now it will auto detect the DBPath directory configured by /etc/pacman.conf. If DBPath is not set, it will fall back to the default /var/lib/pacman/local.

Related issue

Closes #2068

Changes

• Modified src/detection/packages/packages_linux.c. Added a static function getPacmanPackages

Checklist

• I have tested my changes locally.

[Copilot]

Pull request overview

This pull request implements automatic detection of the pacman database path from /etc/pacman.conf configuration file, replacing the hardcoded path. The change allows fastfetch to correctly detect package counts on Arch Linux systems where the DBPath has been customized from the default location.

Changes:

• Added getPacmanPackages() function to parse the DBPath from /etc/pacman.conf
• Modified package counting to use the new function instead of hardcoded path

[Copilot]

The first parameter to ffParsePropFile should be the full path to the config file, not just baseDir->chars. The function should first build the complete path to /etc/pacman.conf by appending it to baseDir, parse the config file from that path, and then restore baseDir to its original length. The correct pattern is: save baseDir->length, append /etc/pacman.conf to baseDir, call ffParsePropFile(baseDir->chars, ...), then restore using ffStrbufSubstrBefore(baseDir, baseDirLen).

Suggested change

	ffStrbufAppendS(&pacmanDir, "/etc/pacman.conf");
	if (!ffParsePropFile(baseDir->chars, "DBPath =", &pacmanDir))
	ffStrbufSetS(&pacmanDir, "/var/lib/pacman");
	ffStrbufSubstrBefore(&pacmanDir, baseDirLen);
	ffStrbufAppendS(baseDir, "/etc/pacman.conf");
	if (!ffParsePropFile(baseDir->chars, "DBPath =", &pacmanDir))
	ffStrbufSetS(&pacmanDir, "/var/lib/pacman");
	ffStrbufSubstrBefore(baseDir, baseDirLen);

[Copilot]

This line attempts to truncate pacmanDir to baseDirLen, but baseDirLen is the length of baseDir, not a valid prefix length for pacmanDir. This line should be removed entirely. After successfully parsing the DBPath from the config file, pacmanDir will already contain just the value from the config file.

Suggested change

	uint32_t baseDirLen = baseDir->length;
	ffStrbufAppendS(&pacmanDir, "/etc/pacman.conf");
	if (!ffParsePropFile(baseDir->chars, "DBPath =", &pacmanDir))
	ffStrbufSetS(&pacmanDir, "/var/lib/pacman");
	ffStrbufSubstrBefore(&pacmanDir, baseDirLen);
	ffStrbufAppendS(&pacmanDir, "/etc/pacman.conf");
	if (!ffParsePropFile(baseDir->chars, "DBPath =", &pacmanDir))
	ffStrbufSetS(&pacmanDir, "/var/lib/pacman");

[Copilot]

The variable pacmanDir is initially set to /etc/pacman.conf but is later used to store the database path value. This is confusing. Instead, baseDir should be used to build the config file path (which will be reset later), and a separate variable should hold the parsed DBPath value, or pacmanDir should start empty and only receive the parsed value.

Suggested change

	ffStrbufAppendS(&pacmanDir, "/etc/pacman.conf");
	if (!ffParsePropFile(baseDir->chars, "DBPath =", &pacmanDir))
	ffStrbufSetS(&pacmanDir, "/var/lib/pacman");
	ffStrbufSubstrBefore(&pacmanDir, baseDirLen);
	ffStrbufAppendS(baseDir, "/etc/pacman.conf");
	if (!ffParsePropFile(baseDir->chars, "DBPath =", &pacmanDir))
	ffStrbufSetS(&pacmanDir, "/var/lib/pacman");
	ffStrbufSubstrBefore(baseDir, baseDirLen);