grep -rlw but only on files that are as newer than 7 days?

Question

Currently, I use this version of grep -rlw

grep -rlw . -e "string_to_search"

To search for overall files containing "string_to_search".

I want to modify it to find files that are not older than 7 days.

How do I do it?

grep -rlw . -e "string_to_search" | find -mtime +7|print

Would something like this work?

Ok this works.find . -mtime -15 -name "*.gz" -exec zgrep -lH "string_to_search" {} \;/ Should I delete the question? — achhainsan, Oct 04 '23 at 07:41
Why do you say 7 in the question and use 15 in the comment with what you claim to be a solution? Also the solution contains clauses that search for and work with gzipped files, the question didn't mention that. I would probably have done something like find . -mtime -7 | xargs grep -lw "string_to_search_for". — Henrik supports the community, Oct 04 '23 at 08:51
Make it an answer @Henriksupportsthecommunity I'll accept it. — achhainsan, Oct 04 '23 at 09:03
@Henriksupportsthecommunity, find -exec is better than find | xargs in that it works with ugly filenames too (xargs by default processes e.g. spaces and quotes specially, not just newlines). Go with find -exec grep ... {} + to run a single grep for many files — ilkkachu, Oct 04 '23 at 09:05
Pretty much the same find+grep in How to run find -exec?, and the general case of find+cmd is also mentioned in Mandatory Reading Question #1: Why does my shell script choke on whitespace or other special characters? (or "Frequently given answer", or however you want to put it.) — ilkkachu, Oct 04 '23 at 09:06
find didn't have the -exec ... + syntax when I first learned of it, so I've never gotten used to it, if I need to handle ugly filenames I usually make find null-terminate the names (with -print0) and make xargs read the null-terminate (with -0). — Henrik supports the community, Oct 04 '23 at 13:15

Stéphane Chazelas · Accepted Answer · 2023-10-04T09:39:09.797

You'd need to use either find or zsh to find the files based on age to pass to grep.

find:

find . -mtime -7 -type f -exec grep -lFw string_to_search {} +

zsh:

grep -lFw -- string_to_search **/*(D.m-7)

Using zsh avoids the ./ prefix added to file paths and give you a sorted list but means we need the -- (for non-POSIX greps such as GNU grep or compatible) to guard against file paths that start with -. The zsh approach could hit the system's execve() limit on the size of arguments+environments which can be worked around using the zargs autoloadable function.

With the GNU implementations of find, sort and xargs, you can also avoid the ./ prefix and sort the list with:

find . -mtime -7 -type f -printf '%P\0' |
  sort -z |
  xargs -r0 grep -lFw -- string_to_search

-mtime -7 and m-7 match on files whose age (based on mtime) rounded down to an integer number of days (a day in this case being a duration of 86400 Unix seconds) is strictly less than 7. So that would be typically those last modified since same time same day last week (or in the future) except when there's been a DST change in the interval.

-mtime +7 would be for ages strictly greater than 7, so for files 8 days (8 * 86400 seconds) old or older.

grep -rlw but only on files that are as newer than 7 days?

1 Answers1