LinuxShell command -- tr

The LinuxShell command -- trtr is used to convert characters from standard input to c or -- complerment to replace all characters not in the first character set. -D or -- delete all the first character set... linux Shell command -- tr is used to replace or delete all characters that are not in the first character set from the standard input for character conversion-c or -- complerment. -D or -- delete deletes all characters that belong to the first character set. -S or -- squeeze-repeats represents consecutive duplicate characters with a separate character. -T or -- the truncate-set1 first deletes the character tr that is longer than the second character set to replace the character from the standard input, delete and compress tr [options] set1 set2 set1 set2 is a character class, character set, the two are always equal digits, echo 12345 is automatically supplemented or discarded without waiting. | tr '0-9' '000000' 9876543210 implements encryption 87654, echo 87654 | tr '000000' 0-9 '9876543210 decrypts the delete character cat file.txt | tr-d 'set1' deletes the content of set1 echo 'who 100' | tr -d '0-9' who character set supplement tr-c [set1] [set2] echo hello 1 char 2 next 4 | tr-d-c '0-9 \ n' 1 2 4 compressed character tr-s [set1] convert multiple spaces into one space echo "gnu is not unix" | tr-s ''GNU IS NOT UNIX