Efficiently Merging Binary Files in Linux: A StepbyStep Guide（linux合并二进制文件）

Efficiently Merging Binary Files in Linux: A Step-by-Step Guide

Merging binary files in Linux is an essential task for many software developers or system administrators. As binary files have specific formats and structures, merging two or more binary files or parts of them requires accurate handling and conversion. In this guide, we’ll discuss efficient methods to merge binary files in Linux step-by-step.

Before starting, you should have a basic knowledge of command-line tools in Linux, such as terminal and shell commands. You’ll also need to install some essential software packages like “binutils” and “hexdump,” which are the most prominent tools used in binary file handling.

Step 1: Identify the Binary File Format and Structure

The first step is to identify the binary file’s format and structure that you want to merge. The format determines the way data is structured in binary files, such as bytes order, data types, and encoding rules. The structure defines the data’s hierarchy, such as headers, sections, tables, and records.

You can use the “file” command to identify the binary file format. For example, to identify a file named “file.bin,” you can run:

$ file file.bin

The output will show the file type and format, such as “ELF 64-bit LSB executable,” “PDF document,” or “JPEG image data.”

To investigate the binary file structure, you can use the “hexdump” command, which displays the file content in hexadecimal and ASCII codes. For example, to display the first 16 bytes of “file.bin,” you can run:

$ hexdump -C -n 16 file.bin

The output will show 16 bytes of the file content, such as:

00000000 4d 5a 90 00 03 00 00 00 04 00 00 00 ff ff 00 00 |MZ…………..|

Step 2: Merge Two Binary Files

If you want to merge two binary files with similar formats and structures, you can use the “objcopy” command, which is part of the “binutils” package. The “objcopy” command can copy one or more sections from one file to another file or merge two files’ sections into a new file.

For example, to merge two files named “file1.bin” and “file2.bin” into a new file named “merged.bin,” you can run:

$ objcopy –input-target=binary –output-target=binary –binary-architecture=i386 file1.bin + file2.bin merged.bin

The command will copy the entire content of “file1.bin” and “file2.bin” into “merged.bin” without any conflicts or overlaps.

Step 3: Merge Specific Sections of Binary Files

If you want to merge specific sections of two binary files, you can use the “objcopy” command with the “–rename-section” option to rename one or more sections of the source files and then merge them into the destination file.

For example, if “file1.bin” has a section named “.text1” and “file2.bin” has a section named “.text2,” and you want to merge these two sections into a new file named “merged.bin,” you can run:

$ objcopy –input-target=binary –output-target=binary –binary-architecture=i386 –rename-section .text1=.text –rename-section .text2=.data file1.bin merged.bin

The command will rename the “.text1” section to “.text” and the “.text2” section to “.data” in “file1.bin,” then merge the renamed sections into “merged.bin.”

Step 4: Merge Parts of Binary Files

If you want to merge only parts of two binary files, you can use the “dd” command, which is a low-level system utility that reads and writes data at the block level.

For example, to extract the last 1024 bytes of “file1.bin” and the first 2048 bytes of “file2.bin” and merge them into a new file named “merged.bin,” you can run:

$ dd if=file1.bin bs=1024 skip=$(($(du -b file1.bin | cut -f 1) – 1024)) of=merged.bin

$ dd if=file2.bin bs=2048 count=1 >> merged.bin

The first “dd” command will read the last 1024 bytes of “file1.bin” and write them to “merged.bin” at the end of the file. The “bs” option specifies the block size, and the “skip” option skips the first blocks of the input file. The “$($(du -b file1.bin | cut -f 1) – 1024)” expression calculates the offset of the last 1024 bytes from the end of the file.

The second “dd” command will read the first 2048 bytes of “file2.bin” and append them to “merged.bin” at the end of the file. The “count” option specifies the number of blocks to read.

Conclusion

Merging binary files in Linux requires special attention and accurate handling of the files’ format and structure. With the right tools and techniques, you can efficiently merge binary files, sections, or parts by following the steps we’ve discussed in this guide. Remember to backup your files before merging or modify them to avoid unwanted data loss or corruption.