#!/bin/sh
#
# for_sh - mind (mind@metalshell.com)
#
# Basic example on the for structure
#
#       [ http://www.metalshell.com ]

# make dir a variable that stores /tmp
dir="/tmp"

# make str a variable that stores: This is our string
str="This is our string"

# make i an integer with 0 as the value
i=0

# for name [ in word ... ] do list done
#
# name: for each segment in a sequence of words name will store each
#       value apon each loop..
#
#       example: str="bleh blah bloop"; for name in $str; do echo $name; done
#       the example would show name being used to store each segment of the
#       string sequence and you would get a result of:
#
#       bleh
#       blah
#       bloop
#
# word: this will be your string sequence shown above: 
#       string="a b c d e f g h, etc.."
#   do: open's your for structure and every statement within it 
#       and 'done' will be executed with each loop.
# list: this is where your commands or statements are placed. This 
#       could also hold other for structure's, if statements, while 
#       loops, anything; possibilities are endless..
# done: close's the for structure but will only be passed when the for 
#       structure and statement's are 'done'..
#
# You can do the same thing below on a shell prompt without writing a script 
# to do it.. if you want to do a for statement on your command prompt you 
# can do it just like the below or you can do it in one command: for file in 
# /dir/*; do echo $file; done
#
# and if you want to do it in more than one you can do it the same as shown 
# below, example:
# mind$ for file in /tmp/*
# > do
# > echo $file
# > done
# /tmp/file1
# /tmp/file2
# ...
#
# The only problem with doing the above is that there is no room for error, 
# after you press enter you cannot go back and fix a problem, the for 
# structure must be broken and rewritten or finished and rewritten, either 
# way you will have to write it all over again.. So if you prefer to do the
# for structure on your command prompt i'd suggest doing it all in one line 
# that way you can fix your mistakes if need be..
#

# start our first for structure
echo "--- \"for file in \$dir/*\" example ---"

for file in $dir/*
do
        # The expr utility evaluates <expression> and writes 
        # the result on standard output.
        # expr <expression>

        # the below would increase $i by 1
        i=`expr $i + 1`
        echo "File #$i: $file"
done

# print a blank line for spacing..
echo

# change our integer back to 0 since we previously had used
# it and the value has changed..
i=0

# start our second for structure
echo "--- \"for seg in \$str\" example ---"
for seg in $str
do
        i=`expr $i + 1`
        echo "Part #$i of our string is: $seg"
done