CODEWITHSUNDEEP
bash
Pororo
Pororo

Reputation: 15

How do I display text on the terminal given line number and filepath?

I have a list of lines of the form

file:starting linenumber:starting column number:ending linenumber:ending column number

That specify a region of text in given files; for example

/home/user/Desktop/helloworld.c:10:5:10:15

What is an efficient way of displaying on screen the corresponding line(s) in helloworld.c? I am pretty sure it is doable with head/tail, but am not too sure about its performance on larger files. If there is a way to also 'prettyprint' the region of text by colouring, that would be great to know about too.

Upvotes: 0

Views: 118

Answers (1)

Socowi
Socowi

Reputation: 27285

Given a single line of the format file:startRow:startCol:endRow:endCol use the following bash function to print the referenced lines and highlight the referenced text:

highlight() {
    IFS=: read -r file srow scol erow ecol <<< "$1"
    shl=$'\033[31m' # start highlight, in this case red text
    ehl=$'\033[0m'  # end highlight, in this case normal text
    sed -n "$erow s/./&$ehl/$ecol;$srow s/./$shl&/$scol;$srow,$erow p;$erow q" "$file"
}

Example usage:

seq -w 1 10000 > file
highlight file:2:4:5:1

prints

output: highlighted text

To process a list of / file with multiple file:startRow:startCol:endRow:endCol use the function inside a loop:

IFS= read -r line; do
    highlight "$line"
done < list

This is not the most efficient approach, since the same file might be read multiple times. However, it probably is efficient enough. I doubt you would notice any delays, even with a lot of large files.

Upvotes: 1

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