Count all occurrences of a string in lots of files with grep

Question

I have a bunch of log files. I need to find out how many times a string occurs in all files.

grep -c string *

returns

...
f         


        

Answer 1

Obligatory AWK solution:

grep -c string * | awk 'BEGIN{FS=":"}{x+=$2}END{print x}'

Take care if your file names include ":" though.

Answer 2

short recursive variant:

find . -type f -exec cat {} + | grep -c 'string'

Answer 3

Another oneliner using basic command line functions handling multiple occurences per line.

 cat * |sed s/string/\\\nstring\ /g |grep string |wc -l

Answer 4

If you want number of occurrences per file (example for string "tcp"):

grep -RIci "tcp" . | awk -v FS=":" -v OFS="\t" '$2>0 { print $2, $1 }' | sort -hr

Example output:

53  ./HTTPClient/src/HTTPClient.cpp
21  ./WiFi/src/WiFiSTA.cpp
19  ./WiFi/src/ETH.cpp
13  ./WiFi/src/WiFiAP.cpp
4   ./WiFi/src/WiFiClient.cpp
4   ./HTTPClient/src/HTTPClient.h
3   ./WiFi/src/WiFiGeneric.cpp
2   ./WiFi/examples/WiFiClientBasic/WiFiClientBasic.ino
2   ./WiFiClientSecure/src/ssl_client.cpp
1   ./WiFi/src/WiFiServer.cpp

Explanation:

• grep -RIci NEEDLE . - looks for string NEEDLE recursively from current directory (following symlinks), ignoring binaries, counting number of occurrences, ignoring case
• awk ... - this command ignores files with zero occurrences and formats lines
• sort -hr - sorts lines in reverse order by numbers in first column

Of course, it works with other grep commands with option -c (count) as well. For example:

grep -c "tcp" *.txt | awk -v FS=":" -v OFS="\t" '$2>0 { print $2, $1 }' | sort -hr

Answer 5

cat * | grep -c string

One of the rare useful applications of cat.

Answer 6

The AWK solution which also handles file names including colons:

grep -c string * | sed -r 's/^.*://' | awk 'BEGIN{}{x+=$1}END{print x}'

Keep in mind that this method still does not find multiple occurrences of string on the same line.