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| -rw-r--r-- | src/od.md | 12 |
1 files changed, 10 insertions, 2 deletions
@@ -11,7 +11,7 @@ -N <n> dump <n> bytes (hex of start with 0x) ``` -## ascii chars to hex string +## ASCII to hex string ```markdown echo -n AAAABBBB | od -An -w4 -tx4 >> 41414141 @@ -23,13 +23,20 @@ >> 177 E L F \n # tc ``` -## extract part of file (eg .rodata section form ELF) +## Extract parts of file +For example `.rodata` section from an elf file. We can use `readelf` to get the +offset into the file where the `.rodata` section starts. ```markdown readelf -W -S foo >> Section Headers: >> [Nr] Name Type Address Off Size ES Flg Lk Inf Al >> ... >> [15] .rodata PROGBITS 00000000004009c0 0009c0 000030 00 A 0 0 16 +``` + +With the offset of `-j 0x0009c0` we can dump `-N 0x30` bytes from the beginning of +the `.rodata` section as follows: +```markdown od -j 0x0009c0 -N 0x30 -tx4 -w4 foo >> 0004700 00020001 >> 0004704 00000000 @@ -39,3 +46,4 @@ >> 0004750 00000003 >> 0004754 00000004 ``` +**Note**: Numbers starting with `0x` will be interpreted as hex by `od`. |