1 .\" DO NOT MODIFY THIS FILE! It was generated by help2man 1.47.3.
2 .TH DD "1" "January 2016" "GNU coreutils 8.25" "User Commands"
4 dd \- convert and copy a file
12 .\" Add any additional description here
14 Copy a file, converting and formatting according to the operands.
17 read and write up to BYTES bytes at a time
20 convert BYTES bytes at a time
23 convert the file as per the comma separated symbol list
26 copy only N input blocks
29 read up to BYTES bytes at a time (default: 512)
32 read from FILE instead of stdin
35 read as per the comma separated symbol list
38 write BYTES bytes at a time (default: 512)
41 write to FILE instead of stdout
44 write as per the comma separated symbol list
47 skip N obs\-sized blocks at start of output
50 skip N ibs\-sized blocks at start of input
53 The LEVEL of information to print to stderr;
54 \&'none' suppresses everything but error messages,
55 \&'noxfer' suppresses the final transfer statistics,
56 \&'progress' shows periodic transfer statistics
58 N and BYTES may be followed by the following multiplicative suffixes:
59 c =1, w =2, b =512, kB =1000, K =1024, MB =1000*1000, M =1024*1024, xM =M
60 GB =1000*1000*1000, G =1024*1024*1024, and so on for T, P, E, Z, Y.
62 Each CONV symbol may be:
71 from ASCII to alternate EBCDIC
74 pad newline\-terminated records with spaces to cbs\-size
77 replace trailing spaces in cbs\-size records with newline
80 change upper case to lower case
83 change lower case to upper case
86 try to seek rather than write the output for NUL input blocks
89 swap every pair of input bytes
92 pad every input block with NULs to ibs\-size; when used
93 with block or unblock, pad with spaces rather than NULs
96 fail if the output file already exists
99 do not create the output file
102 do not truncate the output file
105 continue after read errors
108 physically write output file data before finishing
111 likewise, but also write metadata
113 Each FLAG symbol may be:
116 append mode (makes sense only for output; conv=notrunc suggested)
119 use direct I/O for data
122 fail unless a directory
125 use synchronized I/O for data
128 likewise, but also for metadata
131 accumulate full blocks of input (iflag only)
134 use non\-blocking I/O
137 do not update access time
140 Request to drop cache. See also oflag=sync
143 do not assign controlling terminal from file
146 do not follow symlinks
149 treat 'count=N' as a byte count (iflag only)
152 treat 'skip=N' as a byte count (iflag only)
155 treat 'seek=N' as a byte count (oflag only)
157 Sending a USR1 signal to a running 'dd' process makes it
158 print I/O statistics to standard error and then resume copying.
163 display this help and exit
166 output version information and exit
168 Written by Paul Rubin, David MacKenzie, and Stuart Kemp.
170 GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
172 Report dd translation bugs to <http://translationproject.org/team/>
174 Copyright \(co 2016 Free Software Foundation, Inc.
175 License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
177 This is free software: you are free to change and redistribute it.
178 There is NO WARRANTY, to the extent permitted by law.
180 Full documentation at: <http://www.gnu.org/software/coreutils/dd>
182 or available locally via: info \(aq(coreutils) dd invocation\(aq