How to read first four characters of file name?












0















I have several files whose extensions are .gz with similar filenames to:



ANKR00TUR_R_20183350000_01D_30S_MO.crx.gz


I need to read the first four characters of these files' names and store these characters in a file. How can I do this?






scripts







share|improve this question

























  • The first 4 bytes of the compressed file or of the uncompressed file?

    – PerlDuck
    Jan 7 at 12:04











  • compressed file

    – deepblue_86
    Jan 7 at 12:05
















0















I have several files whose extensions are .gz with similar filenames to:



ANKR00TUR_R_20183350000_01D_30S_MO.crx.gz


I need to read the first four characters of these files' names and store these characters in a file. How can I do this?






scripts







share|improve this question

























  • The first 4 bytes of the compressed file or of the uncompressed file?

    – PerlDuck
    Jan 7 at 12:04











  • compressed file

    – deepblue_86
    Jan 7 at 12:05














0












0








0


0






I have several files whose extensions are .gz with similar filenames to:



ANKR00TUR_R_20183350000_01D_30S_MO.crx.gz


I need to read the first four characters of these files' names and store these characters in a file. How can I do this?






scripts







share|improve this question
















I have several files whose extensions are .gz with similar filenames to:



ANKR00TUR_R_20183350000_01D_30S_MO.crx.gz


I need to read the first four characters of these files' names and store these characters in a file. How can I do this?






scripts




scripts






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Jan 7 at 12:31









Arronical

13.2k84791




13.2k84791










asked Jan 7 at 12:02









deepblue_86deepblue_86

5851023




5851023













  • The first 4 bytes of the compressed file or of the uncompressed file?

    – PerlDuck
    Jan 7 at 12:04











  • compressed file

    – deepblue_86
    Jan 7 at 12:05



















  • The first 4 bytes of the compressed file or of the uncompressed file?

    – PerlDuck
    Jan 7 at 12:04











  • compressed file

    – deepblue_86
    Jan 7 at 12:05

















The first 4 bytes of the compressed file or of the uncompressed file?

– PerlDuck
Jan 7 at 12:04





The first 4 bytes of the compressed file or of the uncompressed file?

– PerlDuck
Jan 7 at 12:04













compressed file

– deepblue_86
Jan 7 at 12:05





compressed file

– deepblue_86
Jan 7 at 12:05










2 Answers
2






active

oldest

votes


















3














Here the code to take first four character of filenames;



filename=ANKR00TUR_R_20183350000_01D_30S_MO.crx.gz

tmp=${filename:0:4}

echo $tmp


Result:



echo "$tmp"



ANKR


Source



For a list



    for file in ./*.gz

    do

       echo "${file:2:4}" | tee -a list.txt

    done


previous for cycle will print on the screen the result and also append to list.txt



Source from Documentation on The Linux Documentation Project (TLDP)



Update
Improvement of code based on @steeldriver suggestion in comment.






share|improve this answer


























  • How can I define 'filename' for all the files (apprx 300) and apply the above code?

    – deepblue_86
    Jan 7 at 12:19













  • they are all in a directory?

    – AtomiX84
    Jan 7 at 12:20











  • yes they are all in a directory.

    – deepblue_86
    Jan 7 at 12:20






  • 1





    Don't use $(ls *.gz) - see Bash Pitfalls #1

    – steeldriver
    Jan 7 at 13:19











  • thanks @steeldriver, I'm always get enough lucky and never encountered problems describe in the link you provide. I have improved the answer based on your suggestion.

    – AtomiX84
    Jan 7 at 13:41



















2














To fetch the first N bytes of a string, cut can be used:



echo ANKR00TUR_R_20183350000_01D_30S_MO.crx.gz | cut --bytes=1-4 > output


This will extract the first 4 bytes from the given string and store it in the file output.



To apply the above code to multiple filenames, use



ls *.gz | cut --bytes=1-4 > output





share|improve this answer


























  • I applied the command but it produced compressed output file and it cannot be extracted.

    – deepblue_86
    Jan 7 at 12:13











  • Yes, that is exactly what you asked for in your question: The first four bytes of the compressed file. Or do you mean the first four bytes of the filename (i.e. ANKR) which is a different case?

    – PerlDuck
    Jan 7 at 12:14













  • yes, i meant the first four bytes of the filename (i.e. ANKR)

    – deepblue_86
    Jan 7 at 12:16











  • @deepblue_86 I updated my answer. Now it fetches the first 4 bytes of the filename instead of the file content.

    – PerlDuck
    Jan 7 at 12:20








  • 1





    @deepblue_86 Please don't ask follow-up questions in comments. Edit your post instead and clarify what you actually need.

    – PerlDuck
    Jan 7 at 12:26











Your Answer








StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "89"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2faskubuntu.com%2fquestions%2f1107705%2fhow-to-read-first-four-characters-of-file-name%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























2 Answers
2






active

oldest

votes








2 Answers
2






active

oldest

votes









active

oldest

votes






active

oldest

votes









3














Here the code to take first four character of filenames;



filename=ANKR00TUR_R_20183350000_01D_30S_MO.crx.gz

tmp=${filename:0:4}

echo $tmp


Result:



echo "$tmp"



ANKR


Source



For a list



    for file in ./*.gz

    do

       echo "${file:2:4}" | tee -a list.txt

    done


previous for cycle will print on the screen the result and also append to list.txt



Source from Documentation on The Linux Documentation Project (TLDP)



Update
Improvement of code based on @steeldriver suggestion in comment.






share|improve this answer


























  • How can I define 'filename' for all the files (apprx 300) and apply the above code?

    – deepblue_86
    Jan 7 at 12:19













  • they are all in a directory?

    – AtomiX84
    Jan 7 at 12:20











  • yes they are all in a directory.

    – deepblue_86
    Jan 7 at 12:20






  • 1





    Don't use $(ls *.gz) - see Bash Pitfalls #1

    – steeldriver
    Jan 7 at 13:19











  • thanks @steeldriver, I'm always get enough lucky and never encountered problems describe in the link you provide. I have improved the answer based on your suggestion.

    – AtomiX84
    Jan 7 at 13:41
















3














Here the code to take first four character of filenames;



filename=ANKR00TUR_R_20183350000_01D_30S_MO.crx.gz

tmp=${filename:0:4}

echo $tmp


Result:



echo "$tmp"



ANKR


Source



For a list



    for file in ./*.gz

    do

       echo "${file:2:4}" | tee -a list.txt

    done


previous for cycle will print on the screen the result and also append to list.txt



Source from Documentation on The Linux Documentation Project (TLDP)



Update
Improvement of code based on @steeldriver suggestion in comment.






share|improve this answer


























  • How can I define 'filename' for all the files (apprx 300) and apply the above code?

    – deepblue_86
    Jan 7 at 12:19













  • they are all in a directory?

    – AtomiX84
    Jan 7 at 12:20











  • yes they are all in a directory.

    – deepblue_86
    Jan 7 at 12:20






  • 1





    Don't use $(ls *.gz) - see Bash Pitfalls #1

    – steeldriver
    Jan 7 at 13:19











  • thanks @steeldriver, I'm always get enough lucky and never encountered problems describe in the link you provide. I have improved the answer based on your suggestion.

    – AtomiX84
    Jan 7 at 13:41














3












3








3







Here the code to take first four character of filenames;



filename=ANKR00TUR_R_20183350000_01D_30S_MO.crx.gz

tmp=${filename:0:4}

echo $tmp


Result:



echo "$tmp"



ANKR


Source



For a list



    for file in ./*.gz

    do

       echo "${file:2:4}" | tee -a list.txt

    done


previous for cycle will print on the screen the result and also append to list.txt



Source from Documentation on The Linux Documentation Project (TLDP)



Update
Improvement of code based on @steeldriver suggestion in comment.






share|improve this answer















Here the code to take first four character of filenames;



filename=ANKR00TUR_R_20183350000_01D_30S_MO.crx.gz

tmp=${filename:0:4}

echo $tmp


Result:



echo "$tmp"



ANKR


Source



For a list



    for file in ./*.gz

    do

       echo "${file:2:4}" | tee -a list.txt

    done


previous for cycle will print on the screen the result and also append to list.txt



Source from Documentation on The Linux Documentation Project (TLDP)



Update
Improvement of code based on @steeldriver suggestion in comment.







share|improve this answer














share|improve this answer



share|improve this answer








edited Jan 7 at 13:40

























answered Jan 7 at 12:17









AtomiX84AtomiX84

68019




68019













  • How can I define 'filename' for all the files (apprx 300) and apply the above code?

    – deepblue_86
    Jan 7 at 12:19













  • they are all in a directory?

    – AtomiX84
    Jan 7 at 12:20











  • yes they are all in a directory.

    – deepblue_86
    Jan 7 at 12:20






  • 1





    Don't use $(ls *.gz) - see Bash Pitfalls #1

    – steeldriver
    Jan 7 at 13:19











  • thanks @steeldriver, I'm always get enough lucky and never encountered problems describe in the link you provide. I have improved the answer based on your suggestion.

    – AtomiX84
    Jan 7 at 13:41



















  • How can I define 'filename' for all the files (apprx 300) and apply the above code?

    – deepblue_86
    Jan 7 at 12:19













  • they are all in a directory?

    – AtomiX84
    Jan 7 at 12:20











  • yes they are all in a directory.

    – deepblue_86
    Jan 7 at 12:20






  • 1





    Don't use $(ls *.gz) - see Bash Pitfalls #1

    – steeldriver
    Jan 7 at 13:19











  • thanks @steeldriver, I'm always get enough lucky and never encountered problems describe in the link you provide. I have improved the answer based on your suggestion.

    – AtomiX84
    Jan 7 at 13:41

















How can I define 'filename' for all the files (apprx 300) and apply the above code?

– deepblue_86
Jan 7 at 12:19







How can I define 'filename' for all the files (apprx 300) and apply the above code?

– deepblue_86
Jan 7 at 12:19















they are all in a directory?

– AtomiX84
Jan 7 at 12:20





they are all in a directory?

– AtomiX84
Jan 7 at 12:20













yes they are all in a directory.

– deepblue_86
Jan 7 at 12:20





yes they are all in a directory.

– deepblue_86
Jan 7 at 12:20




1




1





Don't use $(ls *.gz) - see Bash Pitfalls #1

– steeldriver
Jan 7 at 13:19





Don't use $(ls *.gz) - see Bash Pitfalls #1

– steeldriver
Jan 7 at 13:19













thanks @steeldriver, I'm always get enough lucky and never encountered problems describe in the link you provide. I have improved the answer based on your suggestion.

– AtomiX84
Jan 7 at 13:41





thanks @steeldriver, I'm always get enough lucky and never encountered problems describe in the link you provide. I have improved the answer based on your suggestion.

– AtomiX84
Jan 7 at 13:41













2














To fetch the first N bytes of a string, cut can be used:



echo ANKR00TUR_R_20183350000_01D_30S_MO.crx.gz | cut --bytes=1-4 > output


This will extract the first 4 bytes from the given string and store it in the file output.



To apply the above code to multiple filenames, use



ls *.gz | cut --bytes=1-4 > output





share|improve this answer


























  • I applied the command but it produced compressed output file and it cannot be extracted.

    – deepblue_86
    Jan 7 at 12:13











  • Yes, that is exactly what you asked for in your question: The first four bytes of the compressed file. Or do you mean the first four bytes of the filename (i.e. ANKR) which is a different case?

    – PerlDuck
    Jan 7 at 12:14













  • yes, i meant the first four bytes of the filename (i.e. ANKR)

    – deepblue_86
    Jan 7 at 12:16











  • @deepblue_86 I updated my answer. Now it fetches the first 4 bytes of the filename instead of the file content.

    – PerlDuck
    Jan 7 at 12:20








  • 1





    @deepblue_86 Please don't ask follow-up questions in comments. Edit your post instead and clarify what you actually need.

    – PerlDuck
    Jan 7 at 12:26
















2














To fetch the first N bytes of a string, cut can be used:



echo ANKR00TUR_R_20183350000_01D_30S_MO.crx.gz | cut --bytes=1-4 > output


This will extract the first 4 bytes from the given string and store it in the file output.



To apply the above code to multiple filenames, use



ls *.gz | cut --bytes=1-4 > output





share|improve this answer


























  • I applied the command but it produced compressed output file and it cannot be extracted.

    – deepblue_86
    Jan 7 at 12:13











  • Yes, that is exactly what you asked for in your question: The first four bytes of the compressed file. Or do you mean the first four bytes of the filename (i.e. ANKR) which is a different case?

    – PerlDuck
    Jan 7 at 12:14













  • yes, i meant the first four bytes of the filename (i.e. ANKR)

    – deepblue_86
    Jan 7 at 12:16











  • @deepblue_86 I updated my answer. Now it fetches the first 4 bytes of the filename instead of the file content.

    – PerlDuck
    Jan 7 at 12:20








  • 1





    @deepblue_86 Please don't ask follow-up questions in comments. Edit your post instead and clarify what you actually need.

    – PerlDuck
    Jan 7 at 12:26














2












2








2







To fetch the first N bytes of a string, cut can be used:



echo ANKR00TUR_R_20183350000_01D_30S_MO.crx.gz | cut --bytes=1-4 > output


This will extract the first 4 bytes from the given string and store it in the file output.



To apply the above code to multiple filenames, use



ls *.gz | cut --bytes=1-4 > output





share|improve this answer















To fetch the first N bytes of a string, cut can be used:



echo ANKR00TUR_R_20183350000_01D_30S_MO.crx.gz | cut --bytes=1-4 > output


This will extract the first 4 bytes from the given string and store it in the file output.



To apply the above code to multiple filenames, use



ls *.gz | cut --bytes=1-4 > output






share|improve this answer














share|improve this answer



share|improve this answer








edited Jan 7 at 12:37

























answered Jan 7 at 12:09









PerlDuckPerlDuck

5,86211333




5,86211333













  • I applied the command but it produced compressed output file and it cannot be extracted.

    – deepblue_86
    Jan 7 at 12:13











  • Yes, that is exactly what you asked for in your question: The first four bytes of the compressed file. Or do you mean the first four bytes of the filename (i.e. ANKR) which is a different case?

    – PerlDuck
    Jan 7 at 12:14













  • yes, i meant the first four bytes of the filename (i.e. ANKR)

    – deepblue_86
    Jan 7 at 12:16











  • @deepblue_86 I updated my answer. Now it fetches the first 4 bytes of the filename instead of the file content.

    – PerlDuck
    Jan 7 at 12:20








  • 1





    @deepblue_86 Please don't ask follow-up questions in comments. Edit your post instead and clarify what you actually need.

    – PerlDuck
    Jan 7 at 12:26



















  • I applied the command but it produced compressed output file and it cannot be extracted.

    – deepblue_86
    Jan 7 at 12:13











  • Yes, that is exactly what you asked for in your question: The first four bytes of the compressed file. Or do you mean the first four bytes of the filename (i.e. ANKR) which is a different case?

    – PerlDuck
    Jan 7 at 12:14













  • yes, i meant the first four bytes of the filename (i.e. ANKR)

    – deepblue_86
    Jan 7 at 12:16











  • @deepblue_86 I updated my answer. Now it fetches the first 4 bytes of the filename instead of the file content.

    – PerlDuck
    Jan 7 at 12:20








  • 1





    @deepblue_86 Please don't ask follow-up questions in comments. Edit your post instead and clarify what you actually need.

    – PerlDuck
    Jan 7 at 12:26

















I applied the command but it produced compressed output file and it cannot be extracted.

– deepblue_86
Jan 7 at 12:13





I applied the command but it produced compressed output file and it cannot be extracted.

– deepblue_86
Jan 7 at 12:13













Yes, that is exactly what you asked for in your question: The first four bytes of the compressed file. Or do you mean the first four bytes of the filename (i.e. ANKR) which is a different case?

– PerlDuck
Jan 7 at 12:14







Yes, that is exactly what you asked for in your question: The first four bytes of the compressed file. Or do you mean the first four bytes of the filename (i.e. ANKR) which is a different case?

– PerlDuck
Jan 7 at 12:14















yes, i meant the first four bytes of the filename (i.e. ANKR)

– deepblue_86
Jan 7 at 12:16





yes, i meant the first four bytes of the filename (i.e. ANKR)

– deepblue_86
Jan 7 at 12:16













@deepblue_86 I updated my answer. Now it fetches the first 4 bytes of the filename instead of the file content.

– PerlDuck
Jan 7 at 12:20







@deepblue_86 I updated my answer. Now it fetches the first 4 bytes of the filename instead of the file content.

– PerlDuck
Jan 7 at 12:20






1




1





@deepblue_86 Please don't ask follow-up questions in comments. Edit your post instead and clarify what you actually need.

– PerlDuck
Jan 7 at 12:26





@deepblue_86 Please don't ask follow-up questions in comments. Edit your post instead and clarify what you actually need.

– PerlDuck
Jan 7 at 12:26


















draft saved

draft discarded




















































Thanks for contributing an answer to Ask Ubuntu!


  • Please be sure to answer the question. Provide details and share your research!

But avoid …



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2faskubuntu.com%2fquestions%2f1107705%2fhow-to-read-first-four-characters-of-file-name%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







-

Popular posts from this blog

flock() on closed filehandle LOCK_FILE at /usr/bin/apt-mirror

Image
0 I recently upgraded an Ubuntu 16.04 virtual machine to 18.04. I regularly use this VM to run apt-mirror at school on their high-speed internet, then rsync these files to my rack-mount server at home for updating multiple computers at home without wasting the tiny amount of bandwidth I have there. Since updating I can't get apt-mirror to run on my VM. It keeps giving the error: flock() on closed filehandle LOCK_FILE at /usr/bin/apt-mirror line 214 immediately followed by: apt-mirror is already running, exiting at /usr/bin/apt-mirror line 217 apt-mirror is NOT running, and does not have a cron job. I've tried rebooting, and even looked for the old-style lockfile to delete, but I guess that method is no longer used. Is there some way to force unlock this so I can run apt-mirror? UPDATE: So... I f...
Read more

Mangá

Image
  Nota:  Não confundir com Manga. Mangás e Animes Mangá Mangaká • Tankōbon Film comic La nouvelle manga Mangá original em inglês Anime História Animação influenciada por animes • Filler • OVA • Seiyū Públicos Kodomo • Shōjo • Shōnen Josei • Seinen Gêneros Mahō shōjo • Mecha • Harém Ecchi • Hentai ( Yaoi • Yuri Futanari • Shotacon • Lolicon Toddlercon ) Termos Bishōjo • Chibi • Fan service Gaiden • Kawaii • Kaitō • Light novel Mahō shōnen • Moe (antropomorfismo • Kemonomimi Nekomimi ) • Super deformed Omake • Tsundere • Yonkoma Listas Mangás • Animes • Ecchi • Mangaka • Estúdios • Revistas Fãs ( otaku ) Anime Music Video Convenções • Cosplay Dōjinshi • Fansub • Fandub • Fujoshi OS-tan • Scanlation Portal de Anime e mangá v d e O mangá (português brasileiro) ou manga (português europeu) [ 1 ] (em japonês: 漫画 , manga ? , lit. “história em quadrinhos”) , é a ...
Read more

Eduardo VII do Reino Unido

Image
Eduardo VII Rei do Reino Unido da Grã-Bretanha e Irlanda e dos Domínios Britânicos de Além-mar Imperador da Índia Rei do Reino Unido e Imperador da Índia Reinado 22 de janeiro de 1901 a 6 de maio de 1910 Coroação 9 de agosto de 1902 Delhi Durbar 1 de janeiro de 1903 Predecessora Vitória Sucessor Jorge V   Esposa Alexandra da Dinamarca Descendência Alberto Vitor, Duque de Clarence e Avondale Jorge V do Reino Unido Luísa, Princesa Real Vitória de Gales Maud de Gales Alexandre João de Gales Casa Saxe-Coburgo-Gota Nome completo Alberto Eduardo Nascimento 9 de novembro de 1841   Palácio de Buckingham, Londres, Reino Unido Morte 6 de maio de 1910 (68 anos)   Palácio de Buckingham, Londres, Reino Unido Enterro Capela de São Jorge, Windsor, Berkshire, Reino Unido 20 de maio de 1910 Pai Alberto de Saxe-Coburgo-Gota Mãe Vitória do Reino Unido Assinatura ...
Read more