psh/src/icmd.c
2018-12-17 01:59:10 +01:00

186 lines
3.7 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdarg.h>
#include <string.h>
#include <limits.h>
#include <errno.h>
#include <dirent.h>
#include <sys/types.h>
#include "icmd.h"
#define ICMDS_SIZE \
(sizeof(g_icmds) / sizeof(g_icmds[0])) \
#define ICMD(name) \
{ \
.cmd = #name, \
.len = sizeof(#name) - 1, \
.func = icmd_##name, \
} \
struct icmd
{
char *cmd;
int len;
int (*func)(int, char **);
} g_icmds[] =
{
ICMD(help),
ICMD(echo),
ICMD(exit),
ICMD(cls),
ICMD(cd),
ICMD(ls),
};
#define icmd_die(status, ...) \
{ \
_icmd_die(status, argv[0], __VA_ARGS__); \
return status; \
} \
static void
_icmd_die(int status, char *func, char *format, ...)
{
va_list args;
va_start(args, format);
if (status != 0)
printf("%s: Error: ", func);
vprintf(format, args);
if (status != 0)
putchar('!');
putchar('\n');
if (status < 0)
perror("Reason");
va_end(args);
}
int
call_icmd(int argc, char **argv)
{
size_t i;
for (i = 0; i < ICMDS_SIZE; i++)
if (strncmp(g_icmds[i].cmd, argv[0], g_icmds[i].len) == 0)
return g_icmds[i].func(argc, argv);
return INT_MAX;
}
int
icmd_help(int argc, char **argv)
{
size_t i;
puts(
"\n psh - poor man's shell"
"\n "
"\n internal commands: "
);
for (i = 0; i < ICMDS_SIZE; i++)
printf(" - %s\n", g_icmds[i].cmd);
putchar('\n');
return 0;
}
int
icmd_echo(int argc, char **argv)
{
int i;
for (i = 1; i < argc; i++)
printf("%s%c", argv[i], (argc - i != 1) ? ' ' : '\n');
return 0;
}
int
icmd_exit(int argc, char **argv)
{
puts("good bye!");
exit(0);
return 0;
}
int
icmd_cls(int argc, char **argv)
{
int i = 24;
while (i--)
putchar('\n');
return 0;
}
int
icmd_cd(int argc, char **argv)
{
char def_path[] = ".";
char *path = def_path;
if (argc > 2)
icmd_die(1, "too many arguments given");
if (argc == 2)
path = argv[1];
if (chdir(path))
icmd_die(-1, "could not change directory");
return 0;
}
int
icmd_ls(int argc, char **argv)
{
char def_path[] = ".";
char *path = def_path;
struct dirent *d;
DIR *dir;
int i = 1;
if (argc > 1)
path = argv[1];
do
{
if ((dir = opendir(path)) == NULL)
icmd_die(-1, "could not open directory '%s'", path);
puts(path);
while ((d = readdir(dir)) != NULL)
/* don't print current directory '.' and parent directory '..' */
if (!(d->d_name[0] == '.' && (d->d_name[1] == '\0' || d->d_name[1] == '.')))
printf(" %s\n", d->d_name);
closedir(dir);
putchar('\n');
path = argv[++i];
} while (i < argc);
return 0;
}