如何把二进制数据嵌入到bash脚本里

Step 1: 准备bash脚本

$ cat test.sh
#!/bin/bash

set -euo pipefail

# prepare workdir
#WORK_DIR=/tmp
WORKDIR=$(mktemp -d)

# define the tasks that need to be done with the extracted content
do_work() {
    cd "$WORKDIR"
    # do anything with the extracted content
    echo "DO WORK YOURSELF"
    ls  -l
}

# line number where payload starts
PAYLOAD_BEGIN_LINE=$(awk '/^__PAYLOAD_START_HERE__/ { print NR + 1; exit 0; }' "$0")

# extract the embedded tar file
tail -n +${PAYLOAD_BEGIN_LINE} "$0" | base64 -d | tar -zxpv -C "${WORKDIR}"

# perform actions with the extracted content
do_work

# cleanup workdir
rm -r "${WORKDIR}"

exit 0
# Here's the end of the script followed by the embedded file
# Using following command to append payload:
#   $ tar -zcpvf payload.tgz ...
#   $ base64 payload.tgz >> test.sh
#   or
#   $ tar -zcpv ... | base64 >> test.sh 
__PAYLOAD_START_HERE__

Step 2: 修改脚本函数do_work内容

就是要做具体什么操作。
例如执行其中的命令：

do_work() {
    cd "$WORKDIR"
    # do anything with the extracted content
    echo "DO WORK YOURSELF"
    ls  -l
    ./a.out
}

Step 3: 把二进制内容追加到bash脚本的末尾

$ tar -zcpvf payload.tgz ...
$ base64 payload.tgz >> test.sh

就OK了，然后你就可以运行./test.sh啦。

继续前面的例子：

$ cat test.c
#include <stdio.h>

int main(int argc, char * argv[]) {
   printf("Hello World\n");
   return 0;
}

$ tar -zcpvf payload.tgz a.out
a.out
$ base64 payload.tgz >> test.sh

也可把tar和base64合并成一行：

$ tar -zcpv a.out | base64 >> test.sh