When new files appear on your Linux system (especially after installs/downloads), traditional search utilities won't detect them immediately because they either:

• Rely on pre-built indexes (locate)
• Need explicit directory specification (find)

1. For 'locate' Command

The locate command depends on updatedb which typically runs daily via cron. Force a manual update with:

sudo updatedb
# Verify with:
locate filename.ext

2. For 'find' Command

find doesn't use indexes but requires explicit paths. Best practices:

# Basic scan:
find /path/to/search -name "filename.ext"

# Time-limited search (files modified in last 30 mins):
find / -type f -mmin -30

# Case-insensitive:
find /home -iname "*.deb"

3. Alternative: mlocate

Modern systems often use mlocate instead of traditional locate. Update its database with:

sudo /etc/cron.daily/mlocate  # On Debian/Ubuntu
# Or directly:
sudo /usr/bin/updatedb.mlocate

Partial Directory Rescan

For large systems, limit indexing scope:

sudo updatedb --localpaths='/home /usr/local' --netpaths=''

Real-time Monitoring

For development environments, consider inotify-tools:

sudo apt-get install inotify-tools
inotifywait -m -r /path/to/watch

• Check /etc/updatedb.conf for excluded paths
• Verify cron jobs: sudo cat /etc/cron.daily/mlocate
• For network filesystems: add --netpaths to updatedb

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When working with Linux file search tools like find and locate, a common frustration occurs when newly added files don't appear in search results. This happens because:

• locate relies on a pre-built database (updated via updatedb)
• find performs real-time searches but can be slow for large directories

For locate/updatedb

To manually rebuild the locate database:

# As root or with sudo:
sudo updatedb
# Verify with:
locate filename.ext

For more control over updatedb:

# Update specific directories only
sudo updatedb --localpaths='/path/to/dir /another/path'

For find

No index needed, but here's an optimized find command:

find /search/path -name "*.ext" -type f -mtime -1
# -mtime -1 finds files modified in last 24 hours

mlocate (modern locate)

# Install first:
sudo apt-get install mlocate
# Then use same updatedb command

fd-find (user-friendly alternative)

# Installation:
sudo apt install fd-find
# Basic usage (auto-ignores hidden/vcs files):
fdfind pattern

Edit the cron job for regular updates (usually in /etc/cron.daily/mlocate or similar):

# Example daily update at 3AM
0 3 * * * root /usr/bin/updatedb -f "tmpfs,proc"

For large filesystems:

• Exclude virtual filesystems with -e "tmpfs,proc"
• Limit depth: find / -maxdepth 3 -name pattern
• Use -xdev to stay on single filesystem

If files still don't appear:

# Check updatedb config:
cat /etc/updatedb.conf
# Look for PRUNEPATHS and PRUNEFS exclusions