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--- bash:cut [2019/12/12 21:56] – peter
+++ bash:cut [2021/01/26 15:57] (current) – removed peter
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-====== BASH - cut ======
-The **cut** command allows cutting of sections based on byte positions, characters, or fields separated by a delimiter like the ‘-‘ or ‘:’ characters.
-cut - remove sections from each line of files.
-**cut** can return section based on number of bytes (-b), characters (-c), or fields (-f) when fields are separated by a delimiter(-d).
-<WRAP info>
-Default delimiter is tab.
-</WRAP>
-----
-[[BASH:cut:bytes|bytes]]
-[[BASH:cut:characters|characters]]
-[[BASH:cut:fields|fields]]
-===== Byte Cuts =====
-The **b** option provided by the **cut** utility allows us to cut sections of a text-based on their byte positions.
-Use the cut command with the flag -b followed by the byte numbers for this purpose.
-==== Cut a Single Byte from the Input Stream ====
-<code bash>
-echo "cutting text from input" | cut -b 1
-</code>
-The above command echoes the string “cutting text from input” to the standard output and pipes it as an input to the cut command.
-The cut command will cut just the first byte(c) from this string as only 1 was provided with the -b flag.
-----
-==== Cut Specific Bytes from the Input Stream ====
-<code bash>
-echo "cutting text from input" | cut -b 1,3
-</code>
-This command will only cut the first and third byte of the string “cutting text from input” and will display “ct” as its output.
-----
-==== Cut a Range of Bytes from the Input Stream ====
-<code bash>
-echo "cutting text from input" | cut -b 1-12
-</code>
-The above command will cut the byte range 1-12 from the given string and print out “cutting text” on the standard output.
-<WRAP important>
-**WARNING:** Providing byte ranges that are outside of the string’s occupation will result in a message showing “cut: invalid byte or character range”.
-</WRAP>
-----
-==== Cut a Single Byte from the Text file ====
-<code bash>
-cut -b 1 test.txt
-</code>
-This command will display only the first bytes of each of the five rows inside the file test.txt.
-It is equivalent to the command <code bash>cat test.txt | cut -b 1</code>
------
-==== Cut Specific Bytes from a Text File ====
-<code bash>
-cut -b 1,3 test.txt
-</code>
-The above command cuts only the first and third bytes of each row.
-You can specify any byte numbers as long as they fall within the range of bytes available.
-----
-==== Cut a Range of Bytes from a Text File ====
-<code bash>
-cut -b 1-12 test.txt
-</code>
-This command will output the first one to twelfth bytes of each row in the test.txt file.
-----
-==== Cut from a specific Byte to the End of the Input Stream ====
-<code bash>
-echo "cutting text from input" | cut -b 5-
-</code>
-The above cut command will cut the text from the fifth byte to the end of the string.
-----
-==== Cut from a specific Byte to the End of a File ====
-<code bash>
-cut -b 5- test.txt
-</code>
-This command will start cutting every one of the rows of the file test.txt from the fifth-byte position and finish only after each row ends.
-The trailing hyphen (-) is mandatory for this operation.
-----
-==== Cut a Specified Amount of Bytes from the beginning of a string ====
-<code bash>
-echo "cutting text from input" | cut -b -5
-</code>
-This command will cut the first five bytes of the input string.
-Remember to add the preceding hyphen(-) else the output will not be as expected.
-----
-==== Cut from the First Byte to a Specified Position from a File ====
-<code bash>
-cut -b -5 test.txt
-</code>
-The above command will cut just the first five bytes of each line from the file.
-----
-==== Cut Bytes in Alphabetical Order ====
-<code bash>
-cut -b 1-7 test.txt | sort
-</code>
-The output of the cut command is passed to the sort command for displaying the first seven bytes of each row alphabetically.
-For alphabetical sorting, the sort command doesn’t require any options.
-----
-==== Cut Bytes in Reverse Order ====
-<code bash>
-cut -b 1-7 test.txt | sort -r
-</code>
-This cut command will cut the first 7 bytes from each row and will output them in the reverse order.
-Look how the output of the cut command is being fed to the sort command using a pipe.
-----
-===== Character Cuts =====
-==== Cut a single character ====
-<code bash>
-cut -c 3
-abcdef
-</code>
-returns:
-<code bash>
-c
-</code>
-----
-==== Cut a range of characters ====
-A range must be provided in each case which consists of one of N, N-M, N-(N to last) or -M (first to M)
-<code bash>
-cut -c 2-4
-abcdef
-</code>
-Press CTRL+D to stop inputting
-returns:
-<code bash>
-bcd
-</code>
-----
-==== Cut a variety of characters ====
-<code bash>
-cut -c 2,4,7
-alongtext
-</code>
-returns:
-<code bash>
-lne
-</code>
-----
-==== Cut characters up to a specific position ====
-<code bash>
-cut -c -2
-abcdef
-</code>
-returns:
-<code bash>
-ab
-</code>
-----
-==== Cut characters from a specific position ====
-<code bash>
-cut -c 2-
-abcdef
-</code>
-returns:
-<code bash>
-bcdef
-</code>
-----
-==== Cut various characters ====
-<code bash>
-cut -c 1,6-9,16-
-alongtextwithnospaces
-</code>
-returns:
-<code bash>
-atextspaces
-</code>
-----
-===== Field Cuts =====
-==== Cut fields from a string, using a delimiter ====
-<code bash>
-cut -f 2- -d ':'
-:34:45:56
-</code>
-NOTE: -d specifies delimiter
-returns:
-<code bash>
-:45:56
-</code>
-----
-==== Cut fields from a string, without specifying a delimiter ====
-<code bash>
-cut -f 2
-er rt fg wd ji
-</code>
-returns:
-<code bash>
-er rt fg wd ji
-</code>
-NOTE: cut didn't find the delimiter (default is tab) so returns whole line.
-----
-==== Cut fields from a string, without specifying a delimiter; and prevent printing when delimiter not found ====
-<code bash>
-cut -f 2 -s
-er rt fg wd ji
-</code>
-NOTE: cut wont print as -s flag is used to prevent printing when delimiter not found.
-----
-==== Cut fields from a file, using a delimiter ====
-<code bash>
-cut -d: -f1 /etc/passwd >users.txt
-</code>