sunan laƙabi da laƙabi: umarni biyu ya kamata ku sani

Wasu lokuta wasu koyarwar ana nufin suyi bayani ne game da wasu ka'idoji masu ban mamaki da ban mamaki, a gefe guda, akwai wasu da suka hada da rarraba serial kuma basuda shahara kamar cd, ls, cat, da dai sauransu, amma suna da amfani. A cikin wannan darasin zan nuna muku abin da za a iya yi tare da waɗancan umarnin biyu: sunan uba kuma fada mani.

Wataƙila a priori sun zama kamar wauta a gare ku kuma ba su da wani amfani, amma suna da aikace-aikace masu amfani a wasu lokuta, kamar, misali, a cikin rubutun inda kake buƙatar cire wani ɓangare na hanya, kamar sunan fayil ɗin ko kundin adireshin don wani umarnin yayi aiki akan wannan ...

Me suke yi

Waɗannan dokokin suna da asali, kuma ayyukanta Su ne:

• sunan uba: ana amfani dashi don cire sunan fayil daga hanya.
• sunan laƙabi: ana amfani dashi don cire sunan kundin adireshi daga hanya.

Misalan amfani

Anan zaka iya ganin wasu misalai yadda ake amfani da su:

• Misali, don amfani sunan uba tare da / sauransu / passwd, kuma yana dawo da sunan fayil a fitowar sa, a wannan yanayin passwd:

basename /etc/passwd

• Hakanan zaka iya tantancewa kari saboda haka ya baka sunan fayil din ba tare da fadada ba. Misali, ace kana son cire sunan hoto /home/media/test.jpg ba tare da fadada jpg ba (zai dawo kenan gwaji):

basename -s .jpg /home/media/prueba.jpg

• Kuna iya har ma aiwatar da hanyoyi da yawa lokaci guda daban, don wannan dole ne ku yi amfani da -a zaɓi:

basename -a /etc/passwd /var/log/boot.log

• Don yin akasin haka, kuma ba ku sunan shugabanci, ba tare da sunan fayil ɗin ba, to dole ne ku yi amfani da shi sunan laƙabi. Misali, idan kanaso kayi amfani da shi a cikin hanyar /var/spool/mail/test.txt kuma ka mayar dashi / var / spool / mail, to kayi amfani da:

dirname /var/spool/mail/prueba.txt

Amma ga wani mai amfani a cikin rubutun, a nan kuna da wani misali. Ka yi tunanin kana da rubutu mai sauƙi, kuma a cikin sa akwai wata hanya da za ta iya canzawa. Amma kuna son shi ya nuna kundin adireshin da ke ƙunshe da fayil, ba tare da la'akari da fayil ɗin ba, a wannan yanayin kuna iya samun wani abu kamar:

pathname="/home/usuario/data/fichero"

result=$(dirname "$pathname")

echo $result

A bayyane yake, a cikin wannan rubutun "sunan suna" koyaushe zai kasance daidai ne wanda aka bayyana ta mai ɗorewa a farkon, amma ƙila akwai abubuwan da ba haka bane, kuma wannan shine ya zama mai amfani. Alal misali:

/*script para convertir una imagen gif en png*/

#!/bin/sh
for file in *.gif;do
    #Salir si no hay ficheros
    if [! -f $file];then
        exit
    fi
    b='basename $file .gif'
    echo NOW $b.gif is $b.png
    giftopnm $b.gif | pnmtopng >$b.png
done