Kif taħdem bid-Data u l-Ħin f'Bash Bl-użu tal-Kmand tad-data

Il-kmand tad-data huwa programm bash estern li jippermetti li tissettja jew turi d-data u l-ħin tas-sistema. Jipprovdi wkoll diversi għażliet ta 'ifformattjar. Il-kmand tad-data huwa installat fid-distros kollha tal-Linux b'mod awtomatiku.

$ which date
$ type -a date

Ittajpja kmand tad-data fit-terminal li juri d-data u l-ħin kurrenti.

$ date

L-użu tal-kmand tad-data, id-data tas-sistema, il-ħin u ż-żona tal-ħin jistgħu jiġu modifikati u l-bidla trid tiġi sinkronizzata mal-arloġġ tal-ħardwer.

$ date --set="Thu Nov 12 13:06:59 IST 2020"
$ hwclock --systohc

Post tajjeb biex tikseb il-lista ta 'għażliet ta' formattjar se tkun il-paġna man.

$ man date

Ejja naraw xi wħud mill-aktar għażliet ta 'formattjar komuni li se nużaw.

Biex tapplika l-ifformattjar uża “+ segwit minn “formatter“.
Biex tikseb lista ta' għażliet għall-ifformattjar għal GNU\LINUX agħti ħarsa lejn il-paġna man marbuta.
Biex tikseb lista ta' għażliet ta' formattjar għal BSD agħti ħarsa lejn il-paġna man marbuta.

Iż-żewġ partijiet importanti tal-kmand tad-data qed tuża l-għażla tal-Format +% u –data.

Issa ejja napplikaw xi ifformattjar fuq il-kmand tad-data. Biex tapplika l-ifformattjar, żid is-sinjal plus (+) segwit minn %formatter kif muri fl-eżempji.

Ejja nagħtu ħarsa lejn kif tuża formatters relatati mad-data fi script shell sempliċi imsejjaħ 'date.sh'.

# PRINT YEAR,MONTH,DAY AND DATE...

echo "We are in the year = $(date +%Y)"
echo "We are in the year = $(date +%y)"

# Difference between %Y and %y is %Y will print 4 digits while %y will print the last 2 digits of the year.

echo "We are in the month = $(date +%m)"
echo "We are in the month = $(date +%b)"
echo "We are in the month = $(date +%B)"

# Difference between %B and %b is, %B will print full month name while %b will print abbreviated month name.

echo "Current Day of the month = $(date +%d)"

echo "Current Day of the week = $(date +%A)"
echo "Current Day of the week = $(date +%a)"

# Difference between %A and %a is, %A will print full Weekday name while %a will print abbreviated weekday name.

# Instead of formatting to get the date, we can use %D which will print the date as %m/%d/%y or %F which prints in %Y-%M-%d format.

echo "Date using %D = $(date +%D)"
echo "Date using %F = $(date +%F)"

Ejja nagħtu ħarsa lejn kif tuża formatters relatati mal-ħin fi script shell sempliċi imsejjaħ 'time.sh'.

# PRINT HOURS, MINS, SECONDS, NANO SECONDS

echo Hours = $(date +%H)
echo Minutes = $(date +%M)
echo Seconds = $(date +%S)
echo Nanoseconds = $(date +%N)
echo Epoch Time = $(date +%s)

echo "current time = $(date +%H:%M:%S:%N)"

# can also use %T which displays Time in HH:MM:SS format.

echo "current time in 24 hour format = $(date +%T)"

# can also use %r to display time in 12 hour format.

echo "current time in 12 hour format = $(date +%r)"

B'--date jew -d input tal-bandiera jista' jiġi mgħoddi bħala string u kmand tad-data jaf jimmaniġġaha b'mod intelliġenti.

Ejja naraw xi eżempji biex nifhmu kif taħdem.

# Print yesterday's date and time.
echo "Yesterday = $(date -d "Yesterday")"

# Print Tomorrow date and time.
echo "tomorrow = $(date -d "tomorrow")"

# Find what is the date and time before 10 days from now.
echo "Before 10 days = $(date -d "tomorrow -10 days")"

# Find last month and next month
echo "Last month = $(date -d "last month" "%B")"
echo "Next month = $(date -d "next month" "%B")"

# Find last year and next year
echo "Last Year = $(date -d "last year" "+%Y")"
echo "Next Year = $(date -d "next year" "+%Y")"

# Forecast the weekday
echo "2 days away from today and it comes on weekdays? = $(date -d "Today +2 days" "+%A")

ikkalkula n-numru ta' jiem bejn 2 dati mogħtija.

$ echo $(( ( $(date -d "2020-11-10" "+%s") - $(date -d "2020-11-01" "+%s") ) / 86400))

Sib is-sena mogħtija hija sena biżestili jew le.

$ for y in {2000..2020}; do date -d $y-02-29 &>/dev/null && echo $y is leap year; done

L-għoti tal-output tal-kmand tad-data lil varjabbli.

$ TODAY=$(date +%Y-%m-%d)
OR
$ TODAY1=$(date +%F)
$ echo $TODAY 
$ echo $TODAY1

Oħloq fajls log bid-data miżjuda mal-isem tal-fajl.

Iż-żieda tad-data u l-ħin waqt li noħolqu fajls log, backup, jew fajls tat-test hija operazzjoni komuni li se niltaqgħu magħhom l-aktar spiss. Ejja nieħdu eżempju, biex nieħdu backup, ħloqna script shell.

Dan l-iskritt se jieħu backup minn 00:00 sa 23:59 u skedat li jibda kuljum f'00:00 tal-jum ta' wara. Irridu noħolqu log files bil-format tad-data tal-bieraħ.

CUSTOM_FORMAT=$(date --date "Yesterday" "+%d-%y-%H:%M")
LOG_FILE=/var/log/custom_application/application_${CUSTOM_FORMAT}.log
echo "Script started" >>  ${LOG_FILE}
...
CODE BLOCKS
...
echo "Script completed" >> ${LOG_FILE}

Dak hu għal dan l-artikolu. F'dan l-artikolu, rajna kif tuża d-data u l-ħin tal-bash fil-Linux. Għidilna l-feedback tiegħek.