tr - translate or delete characters
Translate, squeeze, and/or delete characters from standard input, writing to standard output.
use the complement of SET1
delete characters in SET1, do not translate
replace each sequence of a repeated character that is listed in the last specified SET, with a single occurrence of that character
first truncate SET1 to length of SET2
display this help and exit
output version information and exit
SETs are specified as strings of characters. Most represent themselves. Interpreted sequences are:
character with octal value NNN (1 to 3 octal digits)
all characters from CHAR1 to CHAR2 in ascending order
in SET2, copies of CHAR until length of SET1
REPEAT copies of CHAR, REPEAT octal if starting with 0
all letters and digits
all horizontal whitespace
all control characters
all printable characters, not including space
all lower case letters
all printable characters, including space
all punctuation characters
all horizontal or vertical whitespace
all upper case letters
all hexadecimal digits
all characters which are equivalent to CHAR
Translation occurs if -d is not given and both SET1 and SET2 appear. -t may be used only when translating. SET2 is extended to length of SET1 by repeating its last character as necessary. Excess characters of SET2 are ignored. Only [:lower:] and [:upper:] are guaranteed to expand in ascending order; used in SET2 while translating, they may only be used in pairs to specify case conversion. -s uses the last specified SET, and occurs after translation or deletion.
Written by Jim Meyering.
Copyright © 2020 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
or available locally via: info '(coreutils) tr invocation'