Locating and searching file locations

find command

• Type find and specify where the search will be conducted

• ex. find /home -name “files.txt” , this will look for the file in the /home and all subdirectories of /home

• use -name to specify the file

• An output would look like this /home/rtracy/files.txt

The locate command

• Need to install locate on the system

• Then create an index of all files in the file system, index is called locatedb and stored in the /bar/log directory

• Update happens by default daily, when file system changes, an update will be made to the index

the locate command

• Run locate command and specify the file you want to find

• This command searches the index for the text string in a file name

• use /etc/updatedb.conf to configure the behavior of the updatedb utility

Find v locate

• The find command looks through every directory in the path that was specified

• The locate command first builds an index of all files in the system, so when a search is run, it looks at its index, this is more efficient

The which command

• Used to display the full path to a particular shell command or utility

• ex. to find where the ls command resides in the file system use, which ls

The whereis command

• Also used to find files, locate several pieces of information about a file, like source code, binary executable file, and manual page

• ex. whereis ls, this shows the executable location and the man pages for that command’s location

The grep command

• Used to search for a specific text string

• Search for a message, or a specific directive within a configuration file

• ex. grep firewalld /var/log/boot.log , this will search for the text firewalld within a file named boot.log located in the /var/log directory

grep command options

• -i ignores case when searching for the test

• -l (L) option displays only the names of the files that contain the matching text

• -n displays matching line numbers

• -r searches recursively through all subdirectories of the specified path

egrep command and regular expressions

• When searching for more complex patterns such as files using regular expressions instead of a text string

• Regular and metacharacters (Stuff* —> Stuffing, Stuff1, Stuffy)

fgrep command

• Stands for fixing string grep, which is used to search for matching lines of text in the file being searched using direct string comparisons

• Same as running grep with -F option

sed command

• Can capture a text stream and then modify it, you can search through the text stream for certain words to replace with different words

• ex. customers file has phone numbers and the area codes of 801 need to be changed to 435 —> sed -i s/801/435/g customers

awk command

• An enhanced and more powerful version of sed, used to perform more complex stream editing

• Treats a file as if it were a database, and each line is a record, and space between each word creates a new field, name them as $1, $2, etc

• ex. customer file to print all the last names in the file —→ cat customers | awk ‘{print $2}’ , since all the last names are the second word in the file