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--- ubuntu:file:replace_all_occurrences_of_string_within_a_file [2019/11/27 21:29] – created peter
+++ ubuntu:file:replace_all_occurrences_of_string_within_a_file [2022/06/13 11:38] (current) – removed peter
@@ Line 1: / Line 1: @@
-====== Ubuntu - File - Replace all occurrences of string within a file ======
-===== Using awk =====
-Find and replace "dog" or "cat" or "bird" with "pet" on every line and print it out.
-<code bash>
-awk '{gsub(/dog|cat|bird,"pet");print}' filename
-</code>
-Find and replace "dog" with "cat" in every file with extension txt.
-<code bash>
-awk '{gsub("dog", "cat", $0); print > FILENAME}' *.txt
-</code>
-Find cat by itself on it's own line even if there are spaces or tabs before it or after it.  Replace it with dog.  Then print the line.
-<code bash>
-awk '{sub(/^[ \t]*cat .*$/,"dog");print}' filename
-</code>
-Substitute "dog" with "cat" on lines that don't contain the word "pet".
-<code bash>
-awk '!/pet/{gsub(/dog/, "cat")};{print}' filename
-</code>
-----
-===== Using sed =====
-Change all references of the word dog to cat in the file:
-<code bash>
-sed -e 's/dog/cat/g' filename
-</code>
-This uses **sed** to stream edit files, which means change them on the fly.
-Find every line that begins with cat.  In that line replace furry with nothing.  Change the file called filename inline (-i).
-<code bash>
-sed -i '/^cat/{s/furry//}' filename
-</code>
-Find any line starting with the defined shell variable SHELLVAR (notice ' ' around it so it's evaluated).  When the line is found substitute in foo or boo or coo with bar. Edit the file inline.
-<code bash>
-sed -i '/^'${SHELLVAR}'/s/\(foo\|boo\|coo\)/bar/' filename
-</code>