Contents
How to replace multiple patterns at once in Linux?
Text processing is a skill we must master using linux/unix. The last two articles introduced how to delete empty lines in text files and delete lines in text files that contain specified strings. This article mainly introduces how to use the sed command to replace multiple patterns at once.
How to use sed to replace multiple patterns at once?
Let’s take a look at how to use the sed command for multiple patterns replacement. In the following example, we will use the sed command to complete multi-patterns replacement at once, replacing “sed” with “awk” and “command” with “cmd” in the test. If you want to modify the contents of the file directly, you can use the sed -i option.
How to replace multiple patterns in a single pass?
You can perform the substitution by calling re.sub for each key/value pair in the dictionary, thus processing and creating a new copy of the whole text several times, but it is clearly better to do all the changes in a single pass, processing and creating a copy of the text only once.
What are the keys for replacing a pattern in Python?
The keys are the set of strings (or regular-expression patterns) you want to replace, and the corresponding values are the strings with which to replace them.
How to substitute multiple patterns in Linux SED?
You can use any one of the following sed substitute find and replace multiple patterns: sed -e ‘s/Find/Replace/g’ -e ‘s/Find/Replace/g’ <<<“$var” sed -e ‘s/Find/Replace/g’ -e ‘s/Find/Replace/g’ < inputFile > outputFile out=$(sed -e ‘s/Find/Replace/g’ -e ‘s/Find/Replace/g’ <<<“$var”)
When to use sed to replace a multi line string?
Theoretically speaking, there’s no upper bound on the window size of the pattern space. When the size of the file is small, we can practically afford to load the entire file into the pattern space to replace a multi-line string. So, let’s learn this technique of gobbling to solve a few use cases.
Is it possible to fit more than one line in pattern space?
The limitations of nested-reads are best solved by using a set of more sophisticated multi-line compatible commands. With these techniques, we can fit more than one line in the pattern space, each separated by a newline. Let’s understand this by editing non-overlapping structured data in a file.