Use find and grep commands to search for directories that contain one or multiple files with specific content.

I have described three different cases that can be used to locate particular directories: based on a single file, multiple files, or extended single file operations.

Search for mounted devices using a specific option

I will inspect mounted filesystem options to display those mounted in read-write mode.

Locate options file that contains rw line, print directory name.

$ find /proc/fs/ -type f -name options -exec grep -l ^rw$ {} \; | xargs dirname

/proc/fs/ext4/dm-1
/proc/fs/ext4/sda2

Strip leading directory components to display only directory names.

$ find /proc/fs/ -type f -name options -exec grep -l ^rw$ {} \; | xargs dirname | xargs basename -a

or

$ find /proc/fs/ -type f -name options -exec grep -l ^rw$ {} \; | xargs dirname | awk --field-separator '/' '{print $NF}'

dm-1
sda2

Search for path describing a particular USB device

I will inspect idVendor and idProduct files to find the path for Realtek 0bda:5682 device.

$ find -L /sys/bus/usb/devices/ -maxdepth 2 -type f -name idVendor -exec grep -l "0bda" {} \; | \
    while read line; do \
      location=$(dirname $line); \
      grep -q "5682" $location/idProduct;
      if [ "$?" -eq "0" ]; then \
        echo $location;
      fi
    done
/sys/bus/usb/devices/2-5

Search for CPUs running at high speed

I will inspect CPUs frequency and display those running at high speed (> 2 GHz).

$ find /sys/devices/system/cpu -maxdepth 3 -type f -name cpuinfo_cur_freq | \
    while read file; do \
      content=$(sudo cat $file); \
      freq=$(expr $content / 1000); \
      if [ "$freq" -gt "2000" ]; then \
        echo $file | \
          xargs dirname | xargs basename -a | \
          sed s/policy/cpu/; \
      fi \
    done
cpu3
cpu1
ko-fi