Xrisi VI:
vim onoma_script  (dimiourgia/epe3ergasia arxeiou, kalitero)
vi  onoma_script  (enallaktiko)

(Mesa sto VI)
:set mouse=v
na dwseis adeia sto pontiki

i
gia na arxiseis na grafeis

meta epikolisi #!/bin/bash

Esc kai meta :w kai meta 3ana i gia na grafeis
gia na swseis to arxeio XWRIS na bgeis apo to VI

Esc kai meta :wq 
gia na swseis to arxeio kai na bgeis apo to VI

Esc kai meta :q!
gia na bgeis apo to VI XWRIS na swseis to arxeio

chmod +x onoma_script
gia na dwseis dikaiwmata na tre3ei to script.sh

./onoma_script
gia na tre3eis to script.sh

./onoma_script edw ta orismata
gia na tre3eis to script.sh me orismata

meta xana vim onoma_script gia na 3akampeis sto VI






To script prepei PANTA na xekinaei me #!/bin/bash


Telestes sigrisis arithmon
-eq      iso                  if [ "$a" -eq "$b" ]

-ne      aniso                if [ "$a" -ne "$b" ]

-gt      megalitero           if [ "$a" -gt "$b" ]

-ge      megalitero i iso     if [ "$a" -ge "$b" ]

-lt      mikrotero            if [ "$a" -lt "$b" ]

-le      mikrotero i iso      if [ "$a" -le "$b" ]

px
# teskarei an to $a einai 1. An nai leei hi, allios bye
if [ "$a" -eq 1 ]; then
	echo "hi"
else
	echo "bye"
fi


# tsekarei an to $a einai 1. An nai leei hi, allios den leei tipota
if [ "$a" -eq 1 ]; then
	echo "hi"
fi


# tsekarei an to $a einai 1. An nai leei hi, allios, tsekarei an einai 2, an nai leei hey. Allios tipota
if [ "$a" -eq 1 ]; then
	echo "hi"
elif [ "$a" -eq 2 ]; then
	echo "hey"
fi



if [ "$a" -eq 1 ]; then
	echo "hi"
elif [ "$a" -eq 2 ]; then
	echo "hey"
else [ "$a" -gt 3 ]; then
	echo "lol"
fi


An to $a DEN ("!") einai iso me ena, grapse

if ! [ "$a" -eq 1 ]; then
	echo "den einai iso me 1"
fi


Telestes sigrisis keimenou
=     iso

==    iso

!=    aniso

\<    mikrotero (se ASCII)

\>    megalitero (se ASCII)

-z    keimeno me 0 xaraktires

-n    keimeno me >0 xaraktires



Telestes test arxeion

-e    yparxei

-f    einai arxeio

-s    einai 0 bytes

-d    einai directory/katalogos/fakelos


# px teskarei an den yparxei to arxeio tis metavlitis "$1"
if ![ -e "$1" ]; then
	echo "Error: file doesn't exist" >&2
	exit 1
fi


print error: echo "error" >&2    # an 8es na grapseis error
exit me error: exit 1            # an 8es na teleiwsei to programma me sfalma
exit xoris error: exit 0         #                                  xoris sfalma

$#   metavliti pou periexei ton arithmo ton orismaton
$@   metavliti pou periexei ola ta orismata stin seira
$1   metavliti pou periexei to proto orisma
$2   metavliti pou periexei to deftero orisma
$3
$4 klp klp
$?   metavliti pou periexei to status code tis proigoumenis entolis (0 petyxe, 1 apetyxe)

---------------------------

LOOP ORISMATA (ARGUMENTS)
gia ka8e orisma
===========================

for orisma in "$@"
do
    echo "$orisma"
done

---------------------------


Gia ka8e orisma, des an den (!) einai fakelos. An den einai, error kai exit

for arg in "$@"
do
	if ! [ -d "$arg" ]; then
		echo "$arg: not a directory" >&2
		exit 1
	fi
done 



LOOP FILE LINES
gia ka8e seira se ena arxeio
===========================

while read p; do
	echo p;
done < "$1"

---------------------------

Paradeigma
Gia ka8e seira tou arxeiou $1 pros8etei
to periexomeno sto $sum

sum=0
while read p; do
	let "sum=sum+p"
done < "$1"


LOOP FILES IN DIRECTORY
gia ka8e arxeio mesa se enan fakelo
===========================

for file in "$directory"/*; do
	echo "$file"
done

---------------------------



CHECK ORISMATA (ARGUMENTS)
An ta orismata den einai ena, error kai exit
===========================

if [ "$#" -ne 1 ]; then
        echo "Usage: $0 ARG" >&2
        exit 1
fi

---------------------------


CHECK AN (PROTO) ORISMA EINAI FAKELOS
An den (!) einai fakelos, error kai exit
===========================
if ! [ -d "$1" ]; then
	echo "$1: not a directory" >&2
	exit 1
fi
---------------------------



Taxinomisi:
sort

Arithmitiki taxinomisi:
sort -n

Taxinomisi me basi to deftero pedio
sort -n -k 2

Taxinomisi me basi to trito pedio (ta pedia xorizontai me ":")
sort -n -k 3 -t :

Svise diples, triples seires kai krata mono mia:
uniq

To idio, alla dipla exei kai arithmo metrisis tis kathe seiras:
uniq -c

Epilogi protou pediou (ta pedia xorizontai me " " (space):
tr -s " " | cut -d" " -f1

Epilogi defterou pediou (ta pedia xorizontai me "-" (pavla):
cut -d"-" -f2





CHECK AN YPARXOUN ARI8MOI

egrep "[A-Z]" "$1" > /dev/null; # > /dev/null diladi na min graftei to apotelesma stin o8oni

if [ "$?" -eq 0 ]; then
	echo "Yparxoun ari8moi"
fi