head
时间:2006-08-13 来源:anima
head
head [options] [files]
Print the first few lines (default is 10) of one or more files. If files is missing or -, read from standard input. With more than one file, print a header for each file.
Options
-c num[b|k|m] , --bytes num [b|k|m]Print first num bytes or, if num is followed by b, k, or m, first num 512-byte blocks, 1-kilobyte blocks, or 1-megabyte blocks.
--helpDisplay help and then exit.
-n num, --lines num, -numPrint first num lines. Default is 10.
-q, --quiet, --silentQuiet mode; never print headers giving filenames.
-v, --verbosePrint filename headers, even for only one file.
--versionOutput version information and then exit.
Examples
Display the first 20 lines of phone_list:
head -20 phone_list
Display the first 10 phone numbers having a 202 area code:
grep '(202)' phone_list | head