DEV Community

Sérgio Araújo
Sérgio Araújo

Posted on


Print a Random Phrase With Shell Script

Some days ago I came with an idea of getting a random phrase from a file were I am used to save phrases with new English words I am learning. The first draft is this:

#!/usr/bin/env bash
#     Filename:
#      Created: 2019-05-24 07:33
#  Last Change: May 24 2019 08:23
#       Author: Sérgio Araújo - voyeg3r at gmail

# I have a file called phrases were I collect phrases in English
# that I am learning and I had the crazy idea of getting on random phrase

# This script will get a random phrase (the criteria is: paragraphs separated by blank lines)

# target file

# count registers (number of phrases)
# RS -> Register Separator == "" (which means blank lines)
# FS -> Field Separator == "\n" (which means line breaks)
# NR -> prints the register number for all registers
# once we want the number of registers we are getting the last one
COUNT=$(awk 'BEGIN {RS="";FS="\n"} {print NR}' $file | tail -1)

# print a random number: shuf -i 1-10 -n 1
# from the third phrase (the first two are explanatory of the file)
# the last line contains tags, nor a real phrase so I have to get
# from the third paragraph to the end minus one
# var=10 ; echo $((var - 2)) 
RANDPHRASE=$(shuf -i 3-$((COUNT -1)) -n 1)

echo "phrase number: $RANDPHRASE"

# if the NR (number of register) is equal to "number" 
awk -v number=$RANDPHRASE 'BEGIN {RS="";FS="\n"} NR==number' $file
Enter fullscreen mode Exit fullscreen mode

Top comments (0)

An Animated Guide to Node.js Event Loop

>> Check out this classic DEV post <<