14.16 对binary中部更改、尾部追加 https://scz.617.cn/unix/201812031103.txt Q: 对binary的指定区域进行指定字节填充、在binary尾部增加指定大小的空间并进行指 定字节填充，不考虑WinHex这类工具，用shell script如何完成？ 嗯，习惯性抬杠的杠精们可能要问，为啥不用WinHex之类的工具，我犯得着让你知道 为啥吗，稀罕。 A: https://unix.stackexchange.com/questions/66713/how-to-write-file-into-another https://unix.stackexchange.com/questions/146922/is-dd-able-to-overwrite-parts-of-a-file 为了便于演示说明，生造两个二进制文件: $ printf -v escseq \\%o {0..255} $ printf "$escseq" > large $ xxd -g 1 large 00000000: 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f ................ 00000010: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f ................ 00000020: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f !"#$%&'()*+,-./ 00000030: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f 0123456789:;<=>? 00000040: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 00000050: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f PQRSTUVWXYZ[\]^_ 00000060: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f `abcdefghijklmno 00000070: 70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f pqrstuvwxyz{|}~. 00000080: 80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f ................ 00000090: 90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 9e 9f ................ 000000a0: a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa ab ac ad ae af ................ 000000b0: b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 ba bb bc bd be bf ................ 000000c0: c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf ................ 000000d0: d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df ................ 000000e0: e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef ................ 000000f0: f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff ................ $ printf %*s 0x40 | tr " " "\101" > small $ xxd -g 1 small 00000000: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 00000010: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 00000020: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 00000030: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 1) 用small替换large前0x40字节 $ cp large tmp.bin $ dd if=small of=tmp.bin conv=notrunc status=none 或 $ cp large tmp.bin $ cat small 1<> tmp.bin "1<>"表示读写打开、不截断，赋予句柄号1。如果只有">"，表示写打开、截断。dd 的要点是"conv=notrunc"。 $ xxd -g 1 tmp.bin 00000000: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 00000010: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 00000020: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 00000030: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 00000040: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 00000050: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f PQRSTUVWXYZ[\]^_ 00000060: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f `abcdefghijklmno 00000070: 70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f pqrstuvwxyz{|}~. 00000080: 80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f ................ 00000090: 90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 9e 9f ................ 000000a0: a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa ab ac ad ae af ................ 000000b0: b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 ba bb bc bd be bf ................ 000000c0: c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf ................ 000000d0: d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df ................ 000000e0: e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef ................ 000000f0: f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff ................ 2) 生成全零的256字节 $ dd if=/dev/zero of=tmp.bin bs=256 count=1 status=none 3) 生成全0xff的256字节 $ printf %*s 256 | tr " " "\377" > tmp.bin 4) 随机生成256字节 $ dd if=/dev/urandom of=tmp.bin bs=256 count=1 status=none 5) 用small替换large偏移0x80开始的0x40字节 $ cp large tmp.bin $ dd if=small of=tmp.bin obs=$[0x80] seek=1 conv=notrunc status=none 或 $ cp large tmp.bin $ { head -c$[0x80] cat small >&0 } <> tmp.bin > /dev/null 第二种办法完全是奇技淫巧，有dd时还是直接用dd吧。dd的要点是seek。 $ xxd -g 1 tmp.bin 00000000: 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f ................ 00000010: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f ................ 00000020: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f !"#$%&'()*+,-./ 00000030: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f 0123456789:;<=>? 00000040: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 00000050: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f PQRSTUVWXYZ[\]^_ 00000060: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f `abcdefghijklmno 00000070: 70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f pqrstuvwxyz{|}~. 00000080: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 00000090: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 000000a0: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 000000b0: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 000000c0: c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf ................ 000000d0: d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df ................ 000000e0: e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef ................ 000000f0: f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff ................ 6) 用全0xff填充large偏移0x80开始的0x40字节 $ cp large tmp.bin $ printf %*s 0x40 | tr " " "\377" | dd of=tmp.bin obs=$[0x80] seek=1 conv=notrunc status=none 或 $ cp large tmp.bin $ { head -c$[0x80] (printf %*s 0x40 | tr " " "\377") >&0 } <> tmp.bin > /dev/null 注意有对圆括号。 $ xxd -g 1 tmp.bin 00000000: 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f ................ 00000010: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f ................ 00000020: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f !"#$%&'()*+,-./ 00000030: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f 0123456789:;<=>? 00000040: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 00000050: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f PQRSTUVWXYZ[\]^_ 00000060: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f `abcdefghijklmno 00000070: 70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f pqrstuvwxyz{|}~. 00000080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................ 00000090: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................ 000000a0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................ 000000b0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................ 000000c0: c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf ................ 000000d0: d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df ................ 000000e0: e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef ................ 000000f0: f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff ................ 7) 在large尾部追加small $ cat large small > tmp.bin 或 $ cp large tmp.bin $ cat small >> tmp.bin ">>"表示在尾部追加。 $ xxd -g 1 tmp.bin 00000000: 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f ................ 00000010: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f ................ 00000020: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f !"#$%&'()*+,-./ 00000030: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f 0123456789:;<=>? 00000040: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 00000050: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f PQRSTUVWXYZ[\]^_ 00000060: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f `abcdefghijklmno 00000070: 70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f pqrstuvwxyz{|}~. 00000080: 80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f ................ 00000090: 90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 9e 9f ................ 000000a0: a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa ab ac ad ae af ................ 000000b0: b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 ba bb bc bd be bf ................ 000000c0: c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf ................ 000000d0: d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df ................ 000000e0: e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef ................ 000000f0: f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff ................ 00000100: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 00000110: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 00000120: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 00000130: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA 8) 在large尾部追加0x40字节的全0xff $ cp large tmp.bin $ printf %*s 0x40 | tr " " "\377" | dd of=tmp.bin obs=$[0x100] seek=1 conv=notrunc status=none 或 $ printf %*s 0x40 | tr " " "\377" >> tmp.bin $ xxd -g 1 tmp.bin 00000000: 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f ................ 00000010: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f ................ 00000020: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f !"#$%&'()*+,-./ 00000030: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f 0123456789:;<=>? 00000040: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 00000050: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f PQRSTUVWXYZ[\]^_ 00000060: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f `abcdefghijklmno 00000070: 70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f pqrstuvwxyz{|}~. 00000080: 80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f ................ 00000090: 90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 9e 9f ................ 000000a0: a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa ab ac ad ae af ................ 000000b0: b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 ba bb bc bd be bf ................ 000000c0: c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf ................ 000000d0: d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df ................ 000000e0: e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef ................ 000000f0: f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff ................ 00000100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................ 00000110: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................ 00000120: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................ 00000130: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................