sum(1)sum(1)NAMEsum - print checksum and block or byte count of file(s)SYNOPSIS
is obsolescent and should not be used in new applications that are
intended to be portable between systems. Use instead (see cksum(1)).
calculates and prints to standard output a checksum for each named
file, and also prints the size of the file in 512 byte blocks, rounded
The default algorithm is a 16-bit sum of the bytes in which overflow is
ignored. Alternate algorithms can be selected with the and options.
Standard input is used if no file names are given.
is typically used to verify data integrity when copying files between
recognizes the following options:
Use an alternate algorithm in which the 16-bit sum is right
with each byte in computing the checksum.
Use the 32-bit cyclical redundancy check (CRC) algorithm used by
returns the following values upon completion:
All files were processed successfully.
One or more files could not be read or some other error
If an inaccessible file is encountered, continues processing any
remaining files, but the final exit status is affected.
Read error conditions are indistinguishable from end of file on most
devices; check the block or byte count.
This command is likely to be withdrawn from X/Open standards. Applica‐
tions using this command might not be portable to other vendors' plat‐
forms. The usage of cksum(1) is recommended.
SEE ALSOcksum(1), wc(1).