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#include <init/shell.h>
#include <init/stdlib.h>
#include <shared/syscalls.h>
static char *split(char *base) {
while (*base) {
if (*base == ' ' || *base == '\t') {
*base++ = '\0';
return base;
}
base++;
}
return NULL;
}
static int readline(char *buf, size_t max) {
char c;
size_t pos = 0;
while (_syscall_read(__tty_fd, &c, 1, 0)) {
switch (c) {
case '\b':
case 0x7f:
/* for some reason backspace outputs 0x7f (DEL) */
if (pos != 0) {
printf("\b \b");
pos--;
}
break;
case '\r':
printf("\n");
buf[pos++] = '\0';
return pos;
default:
if (pos < max) {
_syscall_write(__tty_fd, &c, 1, 0);
buf[pos] = c;
pos++;
}
}
}
return -1; // error
}
static void cmd_cat(const char *args) {
int fd = _syscall_open(args, strlen(args));
static char buf[256];
int len = 256;
if (fd < 0) {
printf("couldn't open.\n");
return;
}
len = _syscall_read(fd, buf, len, 0);
_syscall_write(__tty_fd, buf, len, 0);
_syscall_close(fd);
}
void shell_loop(void) {
static char cmd[256];
int level = 0;
char *args;
for (;;) {
printf("%x$ ", level);
readline(cmd, 256);
args = split(cmd);
if (!strcmp(cmd, "echo")) {
printf("%s\n", args);
} else if (!strcmp(cmd, "cat")) {
cmd_cat(args);
} else if (!strcmp(cmd, "exit")) {
_syscall_exit(0);
} else if (!strcmp(cmd, "fork")) {
if (_syscall_fork())
_syscall_await();
else level++;
} else {
printf("unknown command :(\n");
}
}
}
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