replacing a string contained withing two strings with an incremental counter in bash

Question

I am trying to change a file looking like this :

>sample_A#Dakota
text
text
text
>text_2#Idao
text
text
text
>junk_1#Alabama
text
text
text
>example_4#Dakota
text
text
text
>example5#Honduras
text
text
text

to a file looking like this :

>model_1#Dakota
text
text
text
>model_2#Idao
text
text
text
>model_3#Alabama
text
text
text
>model_4#Dakota
text
text
text
>model_5#Honduras
text
text
text

So, I need to find the text between > and #, and replace it with "model" followed by an incremental number. I have found some answers only for doing these thing separately, but I haven't been able to combine them. I would want to use bash, with a one-line answer like a sed or an awk. I have tried this :

awk 'BEGIN { cntr = 0 } />/,/#/ { cntr++ ; print "model", cntr } !/>/,/#/ { print $0 }' infile

but I got this :

model 1
text
text
text
model 2
>text_2#Idao
text
text
text
model 3
>junk_1#Alabama
text
text
text
model 4
>example_4#Dakota
text
text
text
model 5
>example5#Honduras
text
text
text

Thanks in advance, T

Answer 1

$ awk '/^>.*#/{sub(/^>[^#]+/, ">model_" ++c)} 1' ip.txt
>model_1#Dakota
text
text
text
>model_2#Idao
text
text
text
>model_3#Alabama
text
text
text
>model_4#Dakota
text
text
text
>model_5#Honduras
text
text
text

• /^>.*#/ if line starts with > and has # in the line
• sub function helps to search and replace first match
• /^>[^#]+/ match characters from start of line from > until just before # character
• ">model_" ++c replacement string
  • c will be zero at the start (since this is numerical context), ++c will give the value after incrementing, so first time we get 1, next time 2 and so on