Removing a newline character at the end of a file
A simpler solution than the accepted one:
truncate -s -1 <<file>>From the truncate man page (man truncate):
-s, --size=SIZE set or adjust the file size by SIZESIZE may also be prefixed by one of the following modifying characters: '+' extend by, '-' reduce by, '<' at most, '>' at least, '/' round down to multiple of, '%' round up to multiple of.
Take advantage of the fact that a) the newline character is at the end of the file and b) the character is 1 byte large: use the truncate command to shrink the file by one byte:
# a file with the word "test" in it, with a newline at the end (5 characters total)$ cat foo test# a hex dump of foo shows the '\n' at the end (0a)$ xxd -p foo746573740a# and `stat` tells us the size of the file: 5 bytes (one for each character)$ stat -c '%s' foo5# so we can use `truncate` to set the file size to 4 bytes instead$ truncate -s 4 foo# which will remove the newline at the end$ xxd -p foo74657374$ cat footest$ You can also roll the sizing and math into a one line command:
truncate -s $(($(stat -c '%s' foo)-1)) foo