Here is a nice trick on how to create a dummy character text file consisting of any chosen or random characters. In the first example we will create and simple file consisting of a single character X with a size of 1000 bytes:
$ < /dev/urandom tr -dc "X" | head -c1000 > file.txt SAMPLE: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
or we can create a file consisting of an alphabetic and numeric character:
$ < /dev/urandom tr -dc "[:alnum:]" | head -c1000 > file.txt SAMPLE: CCjeuAhJNc4yxBfeMbbYX1U1TnSCVS5oiV53MtGoA6s45FAw9H9PyfZJHrA421
Let’s add some TABs and spaces and new line characters:
$ < /dev/urandom tr -dc "\t\n [:alnum:]" | head -c1000 > file.txt SAMPLE: AKelkoPRzlQK9MKO3xzpcfpnbnxNqkBlyn0YfsDZne1 V iZRU5J iKuahZjmeEeTutFQH4ex7UdMmVxxRrqDmiMosdeTmu g0sjFIZb Jox0IXZZGZ2 WSG7pYjpop5AB1gUGAcoJxuTlX
In the last example we will create a random text file of 1000000000 bytes containing any characters, tabs and new lines:
$ < /dev/urandom tr -dc "[:space:][:print:]" | head -c1000000000 > file SAMPLE: *)d qTND;k$=2h#eSY[Cu l1w:M,|.&x}Jzla<rS.=@<Xmd9;Fc @PPD'$I4j?OBk yOP|tEGjr`?B~IT 8pgr$Tpj3mj6v $?:OZw.%h`7s7G4iXDN
Here is how the file looks under the od
microscope:
$ od -a file 0000000 * ) d vt q T N D ; k $ = 2 h # e 0000020 S Y [ C u nl m n 6 . y I | . & x 0000040 } J z l a < r S . = @ < X m d 9 0000060 ; F c cr l 1 w : M , nl vt @ P P D 0000100 ' $ I 4 j ? O B k sp y O P | t E 0000120 G j r ` ? B ~ I T nl 8 p g r $ T 0000140 p j 3 m j 6 v vt $ ? : O Z w . % 0000160 h ` 7 s 7 G 4 i X D N ff 0 d h g 0000200 * N u & ( 9 u ( v I n T - J z ; 0000220 2 v U L : s X a { ) s W U s H 5 0000240 b D > 9 Q sp # & q w H S [ C { vt 0000260 sp cr H ( N ; 5 < g $ ht 0 nl @ 5 O