|
| |
Go to the previous, next
chapter.
These commands output pieces of the input.
head 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 -.
Synopses:
head [option]... [file]...
head -number [option]... [file]...
If more than one file is specicified, head prints a one-line
header consisting of
==> file name
before the output for each file.
head accepts two option formats: the new one, in which numbers are
arguments to the options (-q -n 1), and the old one, in which the number
precedes any option letters (-1q).
The program accepts the following options. Also see section Common options.
- -countoptions -count This option is only recognized
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). -c bytes
--bytes=bytes -c --bytes Print the first bytes
bytes, instead of initial lines. Appending b multiplies bytes by
512, k by 1024, and m by 1048576.
-n n --lines=n -n --lines Output the
first n lines.
-q --quiet --silent -q --quiet --silent Never
print file name headers.
-v --verbose -v --verbose Always print file name headers.
tail prints the last part (10 lines by default) of each file;
it reads from standard input if no files are given or when given a file of -.
Synopses:
tail [option]... [file]...
tail -number [option]... [file]...
tail +number [option]... [file]...
If more than one file is specified, tail prints a one-line
header consisting of
==> file name
before the output for each file.
GNU tail can output any amount of data (some other versions of tail
cannot). It also has no -r option (print in reverse), since reversing a file
is really a different job from printing the end of a file; BSD tail (which is
the one with -r) can only reverse files that are at most as large as its
buffer, which is typically 32k. A more reliable and versatile way to reverse files is the
GNU tac command.
tail accepts two option formats: the new one, in which numbers are
arguments to the options (-n 1), and the old one, in which the number
precedes any option letters (-1 or +1).
If any option-argument is a number n starting with a +, tail
begins printing with the nth item from the start of each file, instead of from
the end.
The program accepts the following options. Also see section Common options.
- -count +count -count +count
This option is only recognized 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 (cfqv).
-c bytes --bytes=bytes -c --bytes
Output the last bytes bytes, instead of final lines. Appending b
multiplies bytes by 512, k by 1024, and m by 1048576.
-f --follow -f --follow Loop forever trying to read more
characters at the end of the file, presumably because the file is growing. Ignored if
reading from a pipe. If more than one file is given, tail prints a header
whenever it gets output from a different file, to indicate which file that output is from.
-n n --lines=n -n --lines Output the
last n lines.
-q -quiet --silent -q --quiet --silent Never
print file name headers.
-v --verbose -v --verbose Always print file name headers.
split creates output files containing consecutive sections of input
(standard input if none is given or input is -). Synopsis:
split [option] [input [prefix]]
By default, split puts 1000 lines of input (or whatever is left
over for the last section), into each output file.
The output files' names consist of prefix (x by default)
followed by a group of letters aa, ab, and so on, such that
concatenating the output files in sorted order by file name produces the original input
file. (If more than 676 output files are required, split uses zaa,
zab, etc.)
The program accepts the following options. Also see section Common options.
- -lines -l lines --lines=lines -l
--lines Put lines lines of input into each output file.
-b
bytes --bytes=bytes -b --bytes Put the
first bytes bytes of input into each output file. Appending b
multiplies bytes by 512, k by 1024, and m by 1048576.
-C bytes --line-bytes=bytes -C --line-bytes
Put into each output file as many complete lines of input as possible without
exceeding bytes bytes. For lines longer than bytes bytes, put bytes
bytes into each output file until less than bytes bytes of the line are left,
then continue normally. bytes has the same format as for the --bytes
option.
csplit creates zero or more output files containing sections of input
(standard input if input is -). Synopsis:
csplit [option]... input pattern...
The contents of the output files are determined by the pattern arguments, as
detailed below. An error occurs if a pattern argument refers to a nonexistent
line of the input file (e.g., if no remaining line matches a given regular expression).
After every pattern has been matched, any remaining input is copied into one
last output file.
By default, csplit prints the number of bytes written to each output file
after it has been created.
The types of pattern arguments are:
- n Create an output file containing the input up to but not including
line n (a positive integer). If followed by a repeat count, also create an
output file containing the next line lines of the input file once for each
repeat.
/regexp/[offset] Create an output file containing
the current line up to (but not including) the next line of the input file that contains a
match for regexp. The optional offset is a + or -
followed by a positive integer. If it is given, the input up to the matching line plus or
minus offset is put into the output file, and the line after that begins the
next section of input.
%regexp%[offset] Like the previous type, except that it
does not create an output file, so that section of the input file is effectively ignored.
{repeat-count} Repeat the previous pattern repeat-count
additional times. repeat-count can either be a positive integer or an asterisk,
meaning repeat as many times as necessary until the input is exausted.
The output files' names consist of a prefix (xx by default) followed by a
suffix. By default, the suffix is an ascending sequence of two-digit decimal numbers from 00
and up to 99. In any case, concatenating the output files in sorted order by
filename produces the original input file.
By default, if csplit encounters an error or receives a hangup, interrupt,
quit, or terminate signal, it removes any output files that it has created so far before
it exits.
The program accepts the following options. Also see section Common options.
- -f prefix --prefix=prefix -f --prefix
Use prefix as the output file name prefix.
-b suffix --suffix=suffix
-b --suffix Use suffix as the output file name suffix. When this
option is specified, the suffix string must include exactly one printf(3)-style
conversion specification, possibly including format specification flags, a field width, a
precision specifications, or all of these kinds of modifiers. The format letter must
convert a binary integer argument to readable form; thus, only d, i,
u, o, x, and X conversions are
allowed. The entire suffix is given (with the current output file number) to sprintf(3)
to form the file name suffixes for each of the individual output files in turn. If this
option is used, the --digits option is ignored.
-n digits --digits=digits -n --digits
Use output file names containing numbers that are digits digits long instead of
the default 2.
-k --keep-files -k --keep-files Do not remove output files
when errors are encountered.
-z --elide-empty-files -z --elide-empty-files Suppress the
generation of zero-length output files. (In cases where the section delimiters of the
input file are supposed to mark the first lines of each of the sections, the first output
file will generally be a zero-length file unless you use this option.) The output file
sequence numbers always run consecutively starting from 0, even when this option is
specified.
-s -q --silent --quiet -s -q --silent --quiet
Do not print counts of output file sizes.
| |
|
