How do I use grep to find multiple words?

How do I grep for multiple patterns?

1. Use single quotes in the pattern: grep ‘pattern*’ file1 file2.
2. Next use extended regular expressions: egrep ‘pattern1|pattern2’ *. py.
3. Finally, try on older Unix shells/oses: grep -e pattern1 -e pattern2 *. pl.
4. Another option to grep two strings: grep ‘word1\|word2’ input.

How do I read an entire file in Perl?

Read an entire file into a string

1. use File::Slurp; my $file_content = read_file(‘text_document.
2. use File::Slurper; my $content = read_text(‘text_document.
3. open my $fh, ‘<‘, ‘text_document.
4. my $file_content = do { local $/; <$fh> };
5. read $fh, my $file_content, -s $fh;
6. open my $fh, ‘<:unix’, ‘text_document.

How do I grep multiple records in Unix?

How do I grep a set of files?

The basic grep syntax when searching multiple patterns in a file includes using the grep command followed by strings and the name of the file or its path. The patterns need to be enclosed using single quotes and separated by the pipe symbol. Use the backslash before pipe | for regular expressions.

How do I access a file in Perl?

Perl open file function You use open() function to open files. The open() function has three arguments: Filehandle that associates with the file. Mode : you can open a file for reading, writing or appending.

How do I input a file in Perl?

1. That would need to be perl -p -e0 textfile. txt or perl -p /dev/null textfile.
2. If you don’t want to put the filename on the command line, I will often hardcode in quick n dirty scripts: @ARGV=”filename. txt”; You can also put the “-p” or a “-n” on the shebang (e.g., #!/usr/bin/perl -p) line.

How to tell if a file exists in Perl?

Perl has a set of useful file test operators that can be used to see whether a file exists or not. Among them is -e , which checks to see if a file exists. This information could be useful to you when you are working on a script that needs access to a specific file, and you want to be sure that the file is there before performing operations.

How to find the file exists in Perl?

in perl, file existence is checked using file operators which are used for checking if the specified file is present or not in the particular directory or folder is known as checking of file existence using file existence operators such as –x operators where particularly we use –e operator for checking of file presence in the directory or folder …

How to append file in Perl?

– We copied content from the file source file c:\emp\est3.txt to destination file c:\emp\est4.txt. – First, we opened source file c:\emp\est3.txt for reading and destination file c:\emp\est4.txt for writing using the open () function. – Second, we read the source file line by line. – Third, we closed the filehandles using the close () function.

Can I upload a file with Perl?

Your Web server must contain the Perl CGI Library, CGI.pm Uploading a file on the Web Server is done with the use of a File upload Form. This File upload form is created on any text editor available and the form must be saved with .htm or .html extension.