Ubuntu searches files by file content

Common command methods for finding file contents in Linux

• Find the line matching the specified string from the file contents:
  $ grep "string found" file name
  Example: Looking for the. In file containing the specified string in the first level folder in the current directory
  grep "Thermcontact" /. In

• Find the line that matches the regular expression from the file contents:
  $ grep–e "Regular expression" file name

• Find is case insensitive:
  $ grep–i "string found" file name

• To find the number of matching rows:
  $ grep-c "string found" file name

• Find rows that do not match the specified string from the file contents:
  $ grep–v "string found" file name

Example

From the root directory, look for all text files with a. log extension and find the line that contains "ERROR"

/-type-name"*.log"|"ERROR"

Find all text files with an. in extension starting from the current directory and find the line containing "Thermcontact"

"*.in"| xargs grep "thermcontact"

Ubuntu searches files by file content