Performance Comparison: grep vs find in Recursive Mode

When it comes to searching for files and patterns in a recursive manner, both grep and find commands can be used. However, depending on the scenario and file system characteristics, one may be more efficient or faster than the other. The following syscall statistics obtained using strace provide insights into the performance comparison of grep and find in recursive mode.

Find Command:

Using the find command with the -exec option to execute grep recursively:

strace -cf find . -type f -exec grep -i -r 'system' {} \;

The syscall statistics obtained are as follows:

% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
65.21    0.286153        2778       103           wait4
5.21     0.022875        16          1475          mmap
4.83     0.021184        17          1250          close
3.42     0.015023        21          702           fcntl
3.41     0.014954        18          838           mprotect
3.25     0.014260        15          921           fstat
2.51     0.011033        17          643           open
1.95     0.008549        16          526           read
... (remaining syscall statistics)

Grep Command:

Using the grep command with the -r and -i options to perform recursive case-insensitive searching:

strace -cf grep -r -i 'system' .

The obtained syscall statistics for the grep command are as follows:

% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
25.61    0.009470        17          550           fcntl
13.45    0.004974        18          271           close
11.53    0.004264        23          184           openat
10.54    0.003898        19          210           read
9.12     0.003372        17          193           fstat
8.93     0.003301        21          156           getdents
... (remaining syscall statistics)

These statistics provide insights into the system calls made by each command during the execution of the recursive search. It’s important to note that the actual performance can vary depending on various factors such as the size and structure of the file system, the number of files and directories, disk speed, and CPU capabilities.

In some scenarios, using find to locate files and then executing grep on each file may provide better performance, especially when dealing with many small files. This approach allows reading a large number of file entries and inodes at once, potentially benefiting from performance improvements on rotating media.

It’s recommended to consider the specific requirements and characteristics of the task at hand and conduct performance tests with representative data to determine which approach is more efficient or faster in a given context.