UNIX for Dummies Questions & Answers

#!/bin/bash    
filename=~/.animals 
echo -n "Enter an animal name: "    
read name    
is_in_file=`grep $name $filename`  
if [ -n "$is_in_file" ]; then 
  echo $is_in_file | cut -d= -f2    
else  
  echo -n "Give me description for $name: " 
  read description 
  echo " $name=$description" >> $filename    
fi

#!/bin/bash
if [ $# -ne 2 ]; then
  echo "Usage:  $0 Animal Description"
  exit
fi

filename=~/.animals 
is_in_file=`grep "$1" $filename`  
if [ -n "$is_in_file" ]; then 
  echo $is_in_file | cut -d= -f2    
else  
  echo " $name=$2" >> $filename    
fi

./zoo.sh "snow leopard" "beautiful but wouldn't like to cross one"

#!/bin/bash    
filename=~/.animals $1 $2   
is_in_file=`grep $name $filename`  
if [ -n "$is_in_file" ]; then 
echo $is_in_file | cut -d= -f2    
else  
echo " $1=$2" >> $filename

#!/bin/bash
if [ $# -ne 2 ]; then
  echo "Usage:  $0 Animal Description"
  exit
fi

filename=~/.animals 
is_in_file=`grep "$1" $filename`  
if [ -n "$is_in_file" ]; then 
  echo $is_in_file | cut -d= -f2    
else  
  echo " $name=$2" >> $filename    
fi

./zoo.sh animal Description

filename=~/.animals

$ cat ~/.animals
cat|hates the dog
dog|ate the cat

$ cat zoo.sh
#!/bin/bash
if [ $# -ne 2 ]; then
  echo "Usage:  $0 Animal Description"
  exit
fi

filename=~/.animals
awk -F"|" -v animal="$1" -v description="$2" '$1 == animal { $2 = description } 1' $filename > $filename.new
mv $filename.new $filename