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head
: Output the first part of fileshead
prints the first part (10 lines by default) of each
file; it reads from standard input if no files are given or
when given a file of -. Synopsis:
head [option]… [file]…
If more than one file is specified, head
prints a
one-line header consisting of:
==> file name <==
before the output for each file.
The program accepts the following options. Also see Common options.
Print the first k bytes, instead of initial lines. However, if k starts with a ‘-’, print all but the last k bytes of each file. k may be, or may be an integer optionally followed by, one of the following multiplicative suffixes:
‘b’ => 512 ("blocks") ‘KB’ => 1000 (KiloBytes) ‘K’ => 1024 (KibiBytes) ‘MB’ => 1000*1000 (MegaBytes) ‘M’ => 1024*1024 (MebiBytes) ‘GB’ => 1000*1000*1000 (GigaBytes) ‘G’ => 1024*1024*1024 (GibiBytes)
and so on for ‘T’, ‘P’, ‘E’, ‘Z’, and ‘Y’.
Output the first k lines. However, if k starts with a ‘-’, print all but the last k lines of each file. Size multiplier suffixes are the same as with the -c option.
Never print file name headers.
Always print file name headers.
For compatibility head
also supports an obsolete option syntax
-countoptions, which is recognized only if it is
specified first. count is a decimal number optionally followed
by a size letter (‘b’, ‘k’, ‘m’) as in -c, or
‘l’ to mean count by lines, or other option letters (‘cqv’).
Scripts intended for standard hosts should use -c count
or -n count instead. If your script must also run on
hosts that support only the obsolete syntax, it is usually simpler to
avoid head
, e.g., by using ‘sed 5q’ instead of
‘head -5’.
An exit status of zero indicates success, and a nonzero value indicates failure.
Next: tail invocation, Up: Output of parts of files [Contents][Index]