rust, 58 bytes

Result

WA

Duration

1171ms

Code [DL]

main(_,s)char*s;{for(;gets(s);)putchar(s[s[1]-s[2]?4:2]);}

stdin

687 765
467 133
877 673
799 988
223 349
664 448
422 484
833 334
565 654
327 224
188 384
935 834
265 564
523 332
195 591
352 891
179 113
521 339
658 587
292 992
433 392
455 998
244 883
914 516
337 644
398 381
515 167
466 287
199 995
364 654
349 298
865 776

stdout

stderr

error: expected one of `!` or `::`, found `(`
 --> /tmp/code.rs:1:5
  |
1 | main(_,s)char*s;{for(;gets(s);)putchar(s[s[1]-s[2]?4:2]);}
  |     ^ expected one of `!` or `::`

error: aborting due to previous error

/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"], 0x7ffde3d8ec50 /* 7 vars */) = 0
11    execve("/usr/bin/realpath", ["realpath", "/volume/CODE"], 0x5633d1353d18 /* 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.rs"], 0x5633d1353d38 /* 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/rustc", ["/usr/bin/rustc", "-o", "/tmp/code", "/tmp/code.rs"], 0x5633d1353d48 /* 7 vars */) = 0
14    +++ exited with 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=3, si_stime=2} ---
15    execve("/bin/cat", ["cat", "-"], 0x5633d1353d08 /* 7 vars */) = 0
16    execve("/tmp/code", ["/tmp/code"], 0x5633d1353cf0 /* 7 vars */) = -1 ENOENT (No such file or directory)
15    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=15, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
16    +++ exited with 127 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=16, si_uid=0, si_status=127, si_utime=0, si_stime=0} ---
17    execve("/bin/rm", ["rm", "/tmp/code.rs", "/tmp/code"], 0x5633d1353cf0 /* 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 +++