As the title reveals it, we are writing a Unix-style shell utility U that is supposed to be invoked (in most cases) from bash.
How exactly could U change the working directory of bash (or parent in general)?
P.S. The shell utility chdir succeeds in doing exactly the same, thus there must be a programmatic way of achieving the effect.
Don't do this.
FILE *p;
char cmd[32];
p = fopen("/tmp/gdb_cmds", "w");
fprintf(p, "call chdir(\"..\")\ndetach\nquit\n");
fclose(p);
sprintf(cmd, "gdb -p %d -batch -x /tmp/gdb_cmds", getppid());
system(cmd);
It will probably work, though note that Bash's pwd
command is cached and won't notice.