Add text to the beginning of every file
While converting a JavaScript create-react-app project to TypeScript, I wanted
a single line of text to every .tsx file. Searching for an answer brought me
to
this question on StackExchange,
specifically this answer.
Using echo and cat, you can add new text to the old file’s contents and send
it to the original file. Combined with a for loop to iterate over the matching
files, I came up with a one-liner1 that saved me a lot of time:
for f in **/*.tsx; do echo "// @ts-nocheck
$(cat "$f")" > "$f"; done
This script looks for all .tsx files in any directory, then adds
// @ts-nocheck and a newline to the beginning of the file. But there is
nothing magic about the selector or added text; you can use whatever you want
for those values.
Hope that saves you a bit of time too!
Happy scripting!
Footnotes
-
Okay, with the newline it’s kind of a two-liner, but you can copy and paste it directly into the command line. ↩