C语言实现获取elf文件section，并将新的文件合并到section中，示例

代码可否提供？

可以的，以下是一个简单的示例代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <elf.h>

int main(int argc, char **argv) {
    if (argc < 4) {
        printf("Usage: %s <elf_file> <section_name> <new_file>\n", argv[0]);
        return 1;
    }

    const char *elf_file = argv[1];
    const char *section_name = argv[2];
    const char *new_file = argv[3];

    FILE *f = fopen(elf_file, "rb");
    if (f == NULL) {
        printf("Error opening file: %s\n", elf_file);
        return 1;
    }

    fseek(f, 0, SEEK_END);
    size_t file_size = ftell(f);
    fseek(f, 0, SEEK_SET);

    char *elf_data = (char *)malloc(file_size);
    fread(elf_data, file_size, 1, f);
    fclose(f);

    Elf32_Ehdr *ehdr = (Elf32_Ehdr *)elf_data;

    if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0) {
        printf("Not an ELF file\n");
        return 1;
    }

    Elf32_Shdr *shdr_start = (Elf32_Shdr *)(elf_data + ehdr->e_shoff);
    Elf32_Shdr *shdr_strtab = shdr_start + ehdr->e_shstrndx;
    char *shstrtab = elf_data + shdr_strtab->sh_offset;

    int section_index = -1;
    for (int i = 0; i < ehdr->e_shnum; i++) {
        Elf32_Shdr *shdr = shdr_start + i;
        char *section_name_at = shstrtab + shdr->sh_name;
        if (strcmp(section_name_at, section_name) == 0) {
            section_index = i;
            break;
        }
    }

    if (section_index == -1) {
        printf("Section not found: %s\n", section_name);
        return 1;
    }

    FILE *new_f = fopen(new_file, "rb");
    if (new_f == NULL) {
        printf("Error opening new file: %s\n", new_file);
        return 1;
    }

    fseek(new_f, 0, SEEK_END);
    size_t new_file_size = ftell(new_f);
    fseek(new_f, 0, SEEK_SET);

    char *new_data = (char *)malloc(new_file_size);
    fread(new_data, new_file_size, 1, new_f);
    fclose(new_f);

    Elf32_Shdr *shdr = shdr_start + section_index;
    char *section_data = elf_data + shdr->sh_offset;
    size_t section_size = shdr->sh_size;

    // Resize the section to fit the new data
    if (new_file_size > section_size) {
        char *new_section_data = (char *)realloc(section_data, new_file_size);
        if (new_section_data == NULL) {
            printf("Error reallocating memory\n");
            return 1;
        }
        section_data = new_section_data;
        memset(section_data + section_size, 0, new_file_size - section_size);
    }

    // Copy the contents of the new file into the section
    memcpy(section_data, new_data, new_file_size);

    // Update the section size
    shdr->sh_size = new_file_size;

    // Write the modified ELF file back to disk
    FILE *out_f = fopen(elf_file, "wb");
    if (out_f == NULL) {
        printf("Error opening output file: %s\n", elf_file);
        return 1;
    }

    fwrite(elf_data, file_size, 1, out_f);
    fclose(out_f);

    printf("Section '%s' updated in file '%s' with contents of file '%s'\n", section_name, elf_file, new_file);

    return 0;
}

这个程序接受三个参数：ELF 文件路径，需要更新的段名和新文件路径。它打开 ELF 文件，查找指定的段，将指定的新文件的内容覆盖到该段中，然后将新的 ELF 文件写回磁盘。您可以将这个程序编译成可执行文件，然后以以下格式运行：

./program <elf_file> <section_name> <new_file>

其中 `<elf_file>` 是需要更新的 ELF 文件的路径，`<section_name>` 是需要更新的段的名字，`<new_file>` 是需要合并到段中的新文件的路径。