I wanted to get words having two occurrences of consecutive repeated characters. The GNU grep(1) also supports Perl-compatible REs as provided by the pcre(3) library. As far as I know, no implementation of Awk supports backreferences within regexp definition. This bug is seen in at least GNU implementations of grep and sed. You can also search the same text in multiple files using grep. grep 'email' test -file This command will display the line in our test-file that contains the word email. Also, specify the name of the file that contains the text. There’s a problem with backreferences in glibc that I found and reported for grep. Find Text in Files To search for text pattern in a file, simply run grep followed by the pattern name. Perl, however, has the same bugs everywhere. Which version you use can give different results. GNU versions, for example, may have some bugs that other implementations may not have. Some other regexp libraries have problems tied to whatever they use to implement them.
#Mac grep perl code#
Sed is Turing complete and Awk is a programming language, so you can write code for it if you wish, in addition to the code you’d need for escaping the metacharacters. Avoid using shell variables to save their contents, since trailing newlines and ASCII NUL characters will require special attention.Īwk and sed do not have an equivalent option to slurp the entire input file content. Note that in the above solution, contents of search.txt and replace.txt are also processed by the Perl command. Print s/\Q$s/$r/gr' search.txt replace.txt ip.txt If I had known about Perl one-liners, I could have easily utilized find and Bash globs to make my life easier, for example: Once, I even opened the files as Vim buffers and applied a bufdo command to see if that would make my workflow simpler. I didn’t know about Perl’s options for one-liners, so I used to modify a script whenever I had to do substitutions for multiple files. I used Vim and Perl for all sorts of text processing needs.
#Mac grep perl how to#
My working knowledge of Linux command line was limited at that time and I didn’t know how to use sed or Awk. One-liners or scripts?įor assembly-level testing of a digital signal processing (DSP) chip, I had to replicate the same scenario for multiple address ranges. However, Perl may have slower performance compared to specialized tools and can be more verbose. Perl has a feature rich regular expression engine, built-in functions, an extensive ecosystem, and is quite portable.
#Mac grep perl portable#
Perl is the most robust portable option for text processing needs. Sometimes you can use Perl either as a single replacement or a complement to them for specific use cases. External commands like grep, sed, Awk, sort, find, or parallel can be combined to work with each other. A shell (like Bash) provides built-in commands and scripting features to easily solve and automate various tasks.
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