Jikwaa faịlụ nke ọma site na iji isi, ọdụ na iwu cat na Linux
Enwere ọtụtụ iwu na mmemme Linux nyere maka ịlele ọdịnaya nke faịlụ. Ịrụ ọrụ na faịlụ bụ otu n'ime ọrụ dị egwu, ọtụtụ n'ime ndị ọrụ kọmputa ka ọ bụrụ onye ọhụrụ, onye ọrụ oge niile, onye ọrụ dị elu, onye mmepụta, onye nchịkwa, wdg na-arụ ọrụ. Iji faịlụ rụọ ọrụ nke ọma na nke ọma bụ nka.
Taa, n'isiokwu a, anyị ga-atụle iwu ndị kachasị ewu ewu a na-akpọ isi, ọdụ na pusi, ọtụtụ n'ime anyị amaralarị iwu ndị dị otú ahụ, ma ole na ole n'ime anyị na-eme ya mgbe ọ dị mkpa.
1. isi Iwu
Iwu isi na-agụ ahịrị iri mbụ nke aha faịlụ ọ bụla enyere. Isi syntax nke isi iwu bụ:
head [options] [file(s)]
Dịka ọmụmaatụ, iwu na-esonụ ga-egosipụta ahịrị iri mbụ nke faịlụ aha ya bụ '/etc/passwd'.
# head /etc/passwd root:x:0:0:root:/root:/bin/bash daemon:x:1:1:daemon:/usr/sbin:/bin/sh bin:x:2:2:bin:/bin:/bin/sh sys:x:3:3:sys:/dev:/bin/sh sync:x:4:65534:sync:/bin:/bin/sync games:x:5:60:games:/usr/games:/bin/sh man:x:6:12:man:/var/cache/man:/bin/sh lp:x:7:7:lp:/var/spool/lpd:/bin/sh mail:x:8:8:mail:/var/mail:/bin/sh news:x:9:9:news:/var/spool/news:/bin/sh
Ọ bụrụ na enyere ihe karịrị otu faịlụ, isi ga-egosi ahịrị iri mbụ nke faịlụ ọ bụla iche iche. Dịka ọmụmaatụ, iwu na-esonụ ga-egosi ahịrị iri nke faịlụ ọ bụla.
# head /etc/passwd /etc/shadow ==> /etc/passwd <== root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin ==> /etc/shadow <== root:$6$85e1:15740:0:99999:7::: bin:*:15513:0:99999:7::: daemon:*:15513:0:99999:7::: adm:*:15513:0:99999:7::: lp:*:15513:0:99999:7::: sync:*:15513:0:99999:7::: shutdown:*:15513:0:99999:7::: halt:*:15513:0:99999:7::: mail:*:15513:0:99999:7::: uucp:*:15513:0:99999:7:::
Ọ bụrụ na achọrọ iweghachite ọnụọgụ ọnụọgụ karịa ahịrị iri, mgbe ahụ, a na-eji nhọrọ '-n' yana integer na-agwa ọnụọgụ nke ahịrị a ga-eweghachi. Dịka ọmụmaatụ, iwu na-esonụ ga-egosipụta ahịrị 5 mbụ site na faịlụ '/var/log/yum.log'.
# head -n5 /var/log/yum.log Jan 10 00:06:49 Updated: openssl-1.0.1e-16.el6_5.4.i686 Jan 10 00:06:56 Updated: openssl-devel-1.0.1e-16.el6_5.4.i686 Jan 10 00:11:42 Installed: perl-Net-SSLeay-1.35-9.el6.i686 Jan 13 22:13:31 Installed: python-configobj-4.6.0-3.el6.noarch Jan 13 22:13:36 Installed: terminator-0.95-3.el6.rf.noarch
N'ezie, ọ dịghị mkpa iji '-n' nhọrọ. Naanị hyphen wee kọwaa ọnụọgụgụ na-enweghị oghere iji nweta otu nsonaazụ ahụ dị ka iwu a dị n'elu.
# head -5 /var/log/yum.log Jan 10 00:06:49 Updated: openssl-1.0.1e-16.el6_5.4.i686 Jan 10 00:06:56 Updated: openssl-devel-1.0.1e-16.el6_5.4.i686 Jan 10 00:11:42 Installed: perl-Net-SSLeay-1.35-9.el6.i686 Jan 13 22:13:31 Installed: python-configobj-4.6.0-3.el6.noarch Jan 13 22:13:36 Installed: terminator-0.95-3.el6.rf.noarch
Iwu isi nwekwara ike igosipụta ọnụọgụ bytes ọ bụla achọrọ site na iji '-c' nhọrọ na-esote ọnụọgụ bytes ga-egosipụta. Dịka ọmụmaatụ, iwu na-esote ga-egosipụta obytes 45 mbụ nke faịlụ enyere.
# head -c45 /var/log/yum.log Jan 10 00:06:49 Updated: openssl-1.0.1e-16.el
2. iwu ọdụ
Iwu ọdụ na-enye gị ohere igosipụta ahịrị iri ikpeazụ nke faịlụ ederede ọ bụla. Yiri iwu isi dị n'elu, iwu ọdụ na-akwado nhọrọ 'n' ọnụọgụ nke mkpụrụedemede na 'n' ọnụọgụ mkpụrụedemede.
Isi syntax nke iwu ọdụ bụ:
# tail [options] [filenames]
Dịka ọmụmaatụ, iwu a ga-ebipụta ahịrị iri ikpeazụ nke faịlụ a na-akpọ 'access.log'.
# tail access.log 1390288226.042 0 172.16.18.71 TCP_DENIED/407 1771 GET http://download.newnext.me/spark.bin? - NONE/- text/html 1390288226.198 0 172.16.16.55 TCP_DENIED/407 1753 CONNECT ent-shasta-rrs.symantec.com:443 - NONE/- text/html 1390288226.210 1182 172.16.20.44 TCP_MISS/200 70872 GET http://mahavat.gov.in/Mahavat/index.jsp pg DIRECT/61.16.223.197 text/html 1390288226.284 70 172.16.20.44 TCP_MISS/304 269 GET http://mahavat.gov.in/Mahavat/i/i-19.gif pg DIRECT/61.16.223.197 - 1390288226.362 570 172.16.176.139 TCP_MISS/200 694 GET http://p4-gayr4vyqxh7oa-3ekrqzjikvrczq44-if-v6exp3-v4.metric.gstatic.com/v6exp3/redir.html pg 1390288226.402 0 172.16.16.55 TCP_DENIED/407 1753 CONNECT ent-shasta-rrs.symantec.com:443 - NONE/- text/html 1390288226.437 145 172.16.18.53 TCP_DENIED/407 1723 OPTIONS http://172.16.25.252/ - NONE/- text/html 1390288226.445 0 172.16.18.53 TCP_DENIED/407 1723 OPTIONS http://172.16.25.252/ - NONE/- text/html 1390288226.605 0 172.16.16.55 TCP_DENIED/407 1753 CONNECT ent-shasta-rrs.symantec.com:443 - NONE/- text/html 1390288226.808 0 172.16.16.55 TCP_DENIED/407 1753 CONNECT ent-shasta-rrs.symantec.com:443 - NONE/- text/html
Ọ bụrụ na enyere ihe karịrị otu faịlụ, ọdụ ga-ebipụta ahịrị iri ikpeazụ nke faịlụ ọ bụla dị ka egosiri n'okpuru.
# tail access.log error.log ==> access.log <== 1390288226.042 0 172.16.18.71 TCP_DENIED/407 1771 GET http://download.newnext.me/spark.bin? - NONE/- text/html 1390288226.198 0 172.16.16.55 TCP_DENIED/407 1753 CONNECT ent-shasta-rrs.symantec.com:443 - NONE/- text/html 1390288226.210 1182 172.16.20.44 TCP_MISS/200 70872 GET http://mahavat.gov.in/Mahavat/index.jsp pg DIRECT/61.16.223.197 text/html 1390288226.284 70 172.16.20.44 TCP_MISS/304 269 GET http://mahavat.gov.in/Mahavat/i/i-19.gif pg DIRECT/61.16.223.197 - 1390288226.362 570 172.16.176.139 TCP_MISS/200 694 GET http://p4-gayr4vyqxh7oa-3ekrqzjikvrczq44-if-v6exp3-v4.metric.gstatic.com/v6exp3/redir.html pg 1390288226.402 0 172.16.16.55 TCP_DENIED/407 1753 CONNECT ent-shasta-rrs.symantec.com:443 - NONE/- text/html 1390288226.437 145 172.16.18.53 TCP_DENIED/407 1723 OPTIONS http://172.16.25.252/ - NONE/- text/html 1390288226.445 0 172.16.18.53 TCP_DENIED/407 1723 OPTIONS http://172.16.25.252/ - NONE/- text/html 1390288226.605 0 172.16.16.55 TCP_DENIED/407 1753 CONNECT ent-shasta-rrs.symantec.com:443 - NONE/- text/html 1390288226.808 0 172.16.16.55 TCP_DENIED/407 1753 CONNECT ent-shasta-rrs.symantec.com:443 - NONE/- text/html ==> error_log <== [Sun Mar 30 03:16:03 2014] [notice] Digest: generating secret for digest authentication ... [Sun Mar 30 03:16:03 2014] [notice] Digest: done [Sun Mar 30 03:16:03 2014] [notice] Apache/2.2.15 (Unix) DAV/2 PHP/5.3.3 mod_ssl/2.2.15 OpenSSL/1.0.0-fips configured -- resuming normal operations
N'otu aka ahụ, ị nwekwara ike ibipụta ahịrị ole na ole ikpeazụ site na iji nhọrọ '-n' dị ka egosiri n'okpuru.
# tail -5 access.log 1390288226.402 0 172.16.16.55 TCP_DENIED/407 1753 CONNECT ent-shasta-rrs.symantec.com:443 - NONE/- text/html 1390288226.437 145 172.16.18.53 TCP_DENIED/407 1723 OPTIONS http://172.16.25.252/ - NONE/- text/html 1390288226.445 0 172.16.18.53 TCP_DENIED/407 1723 OPTIONS http://172.16.25.252/ - NONE/- text/html 1390288226.605 0 172.16.16.55 TCP_DENIED/407 1753 CONNECT ent-shasta-rrs.symantec.com:443 - NONE/- text/html 1390288226.808 0 172.16.16.55 TCP_DENIED/407 1753 CONNECT ent-shasta-rrs.symantec.com:443 - NONE/- text/html
Ị nwekwara ike ibipụta ọnụọgụ mkpụrụedemede site na iji arụmụka '-c' dịka egosiri n'okpuru.
# tail -c5 access.log ymantec.com:443 - NONE/- text/html
3. iwu nwamba
A na-ejikarị iwu 'cat' eme ihe, ngwá ọrụ zuru ụwa ọnụ. Ọ na-eṅomi ndenye ọkọlọtọ na mmepụta ọkọlọtọ. Iwu a na-akwado mpịakọta, ma ọ bụrụ na faịlụ ederede adabaghị na ihuenyo dị ugbu a.
Isi syntax nke iwu pusi bụ:
# cat [options] [filenames] [-] [filenames]
Ojiji nwamba na-ejikarị bụ ịgụ ọdịnaya nke faịlụ. Naanị ihe achọrọ iji mepee faịlụ maka ịgụ bụ pịnye pusi na oghere na aha faịlụ na-esote.
# cat /etc/passwd root:x:0:0:root:/root:/bin/bash daemon:x:1:1:daemon:/usr/sbin:/bin/sh bin:x:2:2:bin:/bin:/bin/sh sys:x:3:3:sys:/dev:/bin/sh sync:x:4:65534:sync:/bin:/bin/sync games:x:5:60:games:/usr/games:/bin/sh man:x:6:12:man:/var/cache/man:/bin/sh lp:x:7:7:lp:/var/spool/lpd:/bin/sh …
Iwu nwamba na-ejikwa ejikọta ọnụ ọgụgụ faịlụ ọnụ.
# echo 'Hi Tecmint-Team' > 1 # echo 'Keep connected' > 2 # echo 'Share your thought' > 3 # echo 'connect us [email ' > 4
# cat 1 2 3 4 > 5
# cat 5 Hi Tecmint-Team Keep connected Share your thought connect us [email
Enwere ike iji ya mepụta faịlụ yana. A na-enweta ya site na igbu pusi na-esote onye ọrụ redirection mmepụta yana aha faịlụ a ga-emepụta.
# cat > tecmint.txt Tecmint is the only website fully dedicated to Linux.
Anyị nwere ike ịnwe onye nrụpụta omenala maka iwu 'cat'. Ebe a na-emejuputa atumatu.
# cat > test.txt << end I am Avishek Here i am writing this post Hope your are enjoying end
# cat test.txt I am Avishek Here i am writing this post Hope your are enjoying
Elelịla ike nke 'cat' iwu ma nwee ike ịba uru maka idegharị faịlụ.
# cat avi.txt I am a Programmer by birth and Admin by profession
# cat avi.txt > avi1.txt
# cat avi1.txt I am a Programmer by birth and Admin by profession
Ugbu a gịnị bụ ihe megidere pusi? Ee, ọ bụ 'tac'. 'tac' bụ iwu n'okpuru Linux. Ọ ka mma igosi ihe atụ nke 'tac' karịa ikwu ihe ọ bụla gbasara ya.
Mepụta faịlụ ederede nwere aha ọnwa niile, ka otu mkpụrụokwu pụtara n'ahịrị.
# cat month January February March April May June July August September October November December
# tac month December November October September August July June May April March February January
Maka ọmụmaatụ ndị ọzọ nke ojiji iwu nwamba, rụtụ aka na 13 cat Command Use
Nke ahụ bụ ihe niile ugbu a. Aga m anọ ebe a ọzọ na edemede ọzọ na-atọ ụtọ, kwesịrị ịmara. Ruo mgbe ahụ nọrọ na nche wee jikọọ na Tecment. Echefula ịnye anyị nzaghachi gị bara uru na ngalaba nkọwa anyị.