jq, 94 bytes

Result

AC

Duration

815ms

Code [DL]

[inputs|sub("K +$";"K")]as$i|"\(.)
"*($i|length)+$i[-1]+"@"*((.|index("T"))-($i[-1]|length)+1)

stdin

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  K                                               

stdout

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  K@@@@@@@@

stderr

strace

11    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffe74ed8220 /* 7 vars */) = 0
12    execve("/bin/cat", ["cat", "-"], 0x556eb2f9dcf8 /* 7 vars */) = 0
12    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=12, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
14    execve("/usr/bin/jq", ["/usr/bin/jq", "-rR", "-f", "/volume/CODE"], 0x556eb3a68350 /* 7 vars */) = 0
13    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=13, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
14    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=14, si_uid=0, si_status=0, si_utime=4, si_stime=0} ---
11    +++ exited with 0 +++