fortran, 120 bytes

Result

AC

Duration

1238ms

Code [DL]

character(51)t,l
read'(a)',t
2 print'(a)',t
read'(a)',l
if(llt(t,l))t(len_trim(l):len_trim(t))=repeat("@",99)
goto 2
end

stdin

          T                                       
                                                  
                                                  
                                                  
                                                  
                                                  
    K                                             

stdout

          T                                        
          T                                        
          T                                        
          T                                        
          T                                        
          T                                        
    @@@@@@@                                        

stderr

At line 4 of file /tmp/code.f08 (unit = 5, file = 'stdin')
Fortran runtime error: End of file

Error termination. Backtrace:
#0  0x7fceaa6ef4af in ???
#1  0x7fceaa6efdf8 in ???
#2  0x7fceaa6f04e3 in ???
#3  0x7fceaa815812 in ???
#4  0x7fceaa815ac6 in ???
#5  0x7fceaa8136da in ???
#6  0x7fceaa816bca in ???
#7  0x7fceaa817862 in ???
#8  0x556ad03fc3d2 in ???
#9  0x556ad03fc583 in ???
#10  0x7fceaa87e228 in ???

strace

10    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffd89f0ffd0 /* 7 vars */) = 0
11    execve("/usr/bin/realpath", ["realpath", "/volume/CODE"], 0x55d200620d18 /* 7 vars */) = 0
11    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=11, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
12    execve("/bin/ln", ["ln", "-sf", "/volume/CODE", "/tmp/code.f08"], 0x55d200620d38 /* 7 vars */) = 0
12    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=12, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
13    execve("/usr/bin/gfortran", ["gfortran", "-std=f2018", "/tmp/code.f08", "-o", "/tmp/code"], 0x55d200e2c068 /* 7 vars */) = 0
14    execve("/usr/libexec/gcc/x86_64-alpine-linux-musl/8.3.0/f951", ["/usr/libexec/gcc/x86_64-alpine-l"..., "/tmp/code.f08", "-quiet", "-dumpbase", "code.f08", "-mtune=generic", "-march=x86-64", "-auxbase", "code", "-std=f2018", "-fintrinsic-modules-path", "/usr/lib/gcc/x86_64-alpine-linux"..., "-o", "/tmp/ccFOGEIE.s"], 0x1b973a0 /* 10 vars */) = 0
14    +++ exited with 0 +++
13    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=14, si_uid=0, si_status=0, si_utime=3, si_stime=0} ---
15    execve("/usr/lib/gcc/x86_64-alpine-linux-musl/8.3.0/../../../../x86_64-alpine-linux-musl/bin/as", ["/usr/lib/gcc/x86_64-alpine-linux"..., "--64", "-o", "/tmp/cckICINp.o", "/tmp/ccFOGEIE.s"], 0x1b973a0 /* 10 vars */) = 0
15    +++ exited with 0 +++
13    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=15, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
16    execve("/usr/libexec/gcc/x86_64-alpine-linux-musl/8.3.0/collect2", ["/usr/libexec/gcc/x86_64-alpine-l"..., "-plugin", "/usr/libexec/gcc/x86_64-alpine-l"..., "-plugin-opt=/usr/libexec/gcc/x86"..., "-plugin-opt=-fresolution=/tmp/cc"..., "-plugin-opt=-pass-through=-lgcc_"..., "-plugin-opt=-pass-through=-lgcc", "-plugin-opt=-pass-through=-lquad"..., "-plugin-opt=-pass-through=-lm", "-plugin-opt=-pass-through=-lgcc_"..., "-plugin-opt=-pass-through=-lgcc", "-plugin-opt=-pass-through=-lc", "-plugin-opt=-pass-through=-lgcc_"..., "-plugin-opt=-pass-through=-lgcc", "--eh-frame-hdr", "--hash-style=gnu", "-m", "elf_x86_64", "--as-needed", "-dynamic-linker", "/lib/ld-musl-x86_64.so.1", "-pie", "-z", "relro", "-z", "now", "-o", "/tmp/code", "/usr/lib/gcc/x86_64-alpine-linux"..., "/usr/lib/gcc/x86_64-alpine-linux"..., "/usr/lib/gcc/x86_64-alpine-linux"..., "-L/usr/lib/gcc/x86_64-alpine-lin"..., ...], 0x1b973a0 /* 12 vars */) = 0
17    execve("/usr/lib/gcc/x86_64-alpine-linux-musl/8.3.0/../../../../x86_64-alpine-linux-musl/bin/ld", ["/usr/lib/gcc/x86_64-alpine-linux"..., "-plugin", "/usr/libexec/gcc/x86_64-alpine-l"..., "-plugin-opt=/usr/libexec/gcc/x86"..., "-plugin-opt=-fresolution=/tmp/cc"..., "-plugin-opt=-pass-through=-lgcc_"..., "-plugin-opt=-pass-through=-lgcc", "-plugin-opt=-pass-through=-lquad"..., "-plugin-opt=-pass-through=-lm", "-plugin-opt=-pass-through=-lgcc_"..., "-plugin-opt=-pass-through=-lgcc", "-plugin-opt=-pass-through=-lc", "-plugin-opt=-pass-through=-lgcc_"..., "-plugin-opt=-pass-through=-lgcc", "--eh-frame-hdr", "--hash-style=gnu", "-m", "elf_x86_64", "--as-needed", "-dynamic-linker", "/lib/ld-musl-x86_64.so.1", "-pie", "-z", "relro", "-z", "now", "-o", "/tmp/code", "/usr/lib/gcc/x86_64-alpine-linux"..., "/usr/lib/gcc/x86_64-alpine-linux"..., "/usr/lib/gcc/x86_64-alpine-linux"..., "-L/usr/lib/gcc/x86_64-alpine-lin"..., ...], 0x7ffce8805f58 /* 12 vars */) = 0
17    +++ exited with 0 +++
16    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=17, si_uid=0, si_status=0, si_utime=0, si_stime=4} ---
16    +++ exited with 0 +++
13    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=16, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
13    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=13, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
18    execve("/bin/cat", ["cat", "-"], 0x55d200620d08 /* 7 vars */ <unfinished ...>
19    execve("/tmp/code", ["/tmp/code"], 0x55d200620cf0 /* 7 vars */ <unfinished ...>
18    <... execve resumed> )            = 0
19    <... execve resumed> )            = 0
18    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=18, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
19    +++ exited with 2 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=19, si_uid=0, si_status=2, si_utime=0, si_stime=0} ---
20    execve("/bin/rm", ["rm", "/tmp/code.f08", "/tmp/code"], 0x55d200620cf0 /* 7 vars */) = 0
20    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=20, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
10    +++ exited with 0 +++