c-gcc, 53 bytes

Result

WA

Duration

793ms

Code [DL]

main(){for(i,j;gets(&j);putchar(j%257-32?i:j))j>>=8;}

stdin

891 971
552 832
544 448
598 374
259 299
488 386
711 916
588 778
122 974
498 991
978 772
288 448
995 943
323 996
831 313
599 941
951 587
458 589
241 142
492 227
131 126
155 711
926 821
334 443
942 725
799 953
151 754
687 334
195 167
344 448
174 494
262 262

stdout

stderr

/tmp/code.c:1:1: warning: return type defaults to 'int' [-Wimplicit-int]
    1 | main(){for(i,j;gets(&j);putchar(j%257-32?i:j))j>>=8;}
      | ^~~~
/tmp/code.c: In function 'main':
/tmp/code.c:1:12: error: 'i' undeclared (first use in this function)
    1 | main(){for(i,j;gets(&j);putchar(j%257-32?i:j))j>>=8;}
      |            ^
/tmp/code.c:1:12: note: each undeclared identifier is reported only once for each function it appears in
/tmp/code.c:1:14: error: 'j' undeclared (first use in this function)
    1 | main(){for(i,j;gets(&j);putchar(j%257-32?i:j))j>>=8;}
      |              ^
/tmp/code.c:1:13: warning: left-hand operand of comma expression has no effect [-Wunused-value]
    1 | main(){for(i,j;gets(&j);putchar(j%257-32?i:j))j>>=8;}
      |             ^
/tmp/code.c:1:16: warning: implicit declaration of function 'gets' [-Wimplicit-function-declaration]
    1 | main(){for(i,j;gets(&j);putchar(j%257-32?i:j))j>>=8;}
      |                ^~~~
/tmp/code.c:1:25: warning: implicit declaration of function 'putchar' [-Wimplicit-function-declaration]
    1 | main(){for(i,j;gets(&j);putchar(j%257-32?i:j))j>>=8;}
      |                         ^~~~~~~
/root/script: line 7: /tmp/code: not found
rm: can't remove '/tmp/code': No such file or directory

strace

10    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE.c"], 0x7fffe3f018f0 /* 7 vars */) = 0
11    execve("/usr/bin/realpath", ["realpath", "/volume/CODE.c"], 0x562c827a9d20 /* 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.c", "/tmp/code.c"], 0x562c827a9d40 /* 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/gcc", ["gcc", "-Wall", "-O2", "-std=c99", "/tmp/code.c", "-o", "/tmp/code", "-lm"], 0x562c8467c0d8 /* 7 vars */) = 0
14    execve("/usr/libexec/gcc/x86_64-alpine-linux-musl/9.3.0/cc1", ["/usr/libexec/gcc/x86_64-alpine-l"..., "-quiet", "/tmp/code.c", "-quiet", "-dumpbase", "code.c", "-mtune=generic", "-march=x86-64", "-auxbase", "code", "-O2", "-Wall", "-std=c99", "-o", "/tmp/cccccPFF.s"], 0x1685020 /* 10 vars */) = 0
14    +++ exited with 1 +++
13    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=14, si_uid=0, si_status=1, si_utime=0, si_stime=0} ---
13    +++ exited with 1 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=13, si_uid=0, si_status=1, si_utime=0, si_stime=0} ---
15    execve("/bin/cat", ["cat", "-"], 0x562c827a9d08 /* 7 vars */) = 0
16    execve("/tmp/code", ["/tmp/code"], 0x562c827a9cf0 /* 7 vars */) = -1 ENOENT (No such file or directory)
16    +++ exited with 127 +++
15    --- SIGPIPE {si_signo=SIGPIPE, si_code=SI_USER, si_pid=15, si_uid=0} ---
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=16, si_uid=0, si_status=127, si_utime=0, si_stime=0} ---
15    +++ killed by SIGPIPE +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_KILLED, si_pid=15, si_uid=0, si_status=SIGPIPE, si_utime=0, si_stime=0} ---
17    execve("/bin/rm", ["rm", "/tmp/code.c", "/tmp/code"], 0x562c827a9cf0 /* 7 vars */) = 0
17    +++ exited with 1 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=17, si_uid=0, si_status=1, si_utime=0, si_stime=0} ---
10    +++ exited with 1 +++