Linux head command is used to output the first 10 lines of a file. By default, when you head a file, it will list first 10 lines as the output, you can pass the options to output more number of lines which is listed below with great examples.
head - output the first part of files
head [OPTION]... [FILE]...
Print the first 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name. With no FILE, or when FILE is -, read standard input. Mandatory arguments to long options are mandatory for short options too. -c, --bytes=[-]NUM print the first NUM bytes of each file; with the leading '-', print all but the last NUM bytes of each file -n, --lines=[-]NUM print the first NUM lines instead of the first 10; with the leading '-', print all but the last NUM lines of each file -q, --quiet, --silent never print headers giving file names -v, --verbose always print headers giving file names -z, --zero-terminated line delimiter is NUL, not newline --help display this help and exit --version output version information and exit NUM may have a multiplier suffix: b 512, kB 1000, K 1024, MB 1000*1000, M 1024*1024, GB 1000*1000*1000, G 1024*1024*1024, and so on for T, P, E, Z, Y. Binary prefixes can be used, too: KiB=K, MiB=M, and so on.
First 10 lines:
head dpkg.log command by default only list first 10 lines, even the file has 10000+ lines.
root@letusstudy:/var/log# head dpkg.log 2020-04-01 06:50:47 startup archives unpack 2020-04-01 06:50:47 upgrade libquadmath0:amd64 8.3.0-26ubuntu1~18.04 8.4.0-1ubuntu1~18.04 2020-04-01 06:50:47 status triggers-pending libc-bin:amd64 2.27-3ubuntu1 2020-04-01 06:50:47 status half-configured libquadmath0:amd64 8.3.0-26ubuntu1~18.04 2020-04-01 06:50:47 status unpacked libquadmath0:amd64 8.3.0-26ubuntu1~18.04 2020-04-01 06:50:47 status half-installed libquadmath0:amd64 8.3.0-26ubuntu1~18.04 2020-04-01 06:50:47 status half-installed libquadmath0:amd64 8.3.0-26ubuntu1~18.04 2020-04-01 06:50:47 status unpacked libquadmath0:amd64 8.4.0-1ubuntu1~18.04 2020-04-01 06:50:47 status unpacked libquadmath0:amd64 8.4.0-1ubuntu1~18.04 2020-04-01 06:50:48 upgrade libitm1:amd64 8.3.0-26ubuntu1~18.04 8.4.0-1ubuntu1~18.04 root@letusstudy:/var/log#
First 15 lines:
head -15 dpkg.log will list first 15 lines.
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