LibC: Implement getopt()

This commit is contained in:
Bananymous 2024-02-14 15:00:58 +02:00
parent 198dde8365
commit 4cd9abdd15
2 changed files with 86 additions and 1 deletions

View File

@ -160,7 +160,7 @@ long gethostid(void);
int gethostname(char* name, size_t namelen); int gethostname(char* name, size_t namelen);
char* getlogin(void); char* getlogin(void);
int getlogin_r(char* name, size_t namesize); int getlogin_r(char* name, size_t namesize);
int getopt(int argc, char* const argv[], const char* optstring); int getopt(int argc, char* const argv[], const char* optstring);
pid_t getpgid(pid_t pid); pid_t getpgid(pid_t pid);
pid_t getpgrp(void); pid_t getpgrp(void);
pid_t getpid(void); pid_t getpid(void);

View File

@ -295,6 +295,91 @@ int rmdir(const char* path)
return syscall(SYS_UNLINK, path); return syscall(SYS_UNLINK, path);
} }
char* optarg = nullptr;
int opterr = 1;
int optind = 1;
int optopt = 0;
int getopt(int argc, char* const argv[], const char* optstring)
{
if (optind >= argc)
return -1;
static int idx = 1;
const char* current = argv[optind];
// if "--" is encountered, no more options are parsed
if (idx == -1)
return -1;
// if current is nullptr, does not start with '-' or is string "-", return -1
if (current == nullptr || current[0] != '-' || current[1] == '\0')
return -1;
// if current points to string "--" increment optind and return -1
if (current[1] == '-' && current[2] == '\0')
{
idx = -1;
optind++;
return -1;
}
for (size_t i = 0; optstring[i]; i++)
{
if (optstring[i] == ':')
continue;
if (current[idx] != optstring[i])
continue;
if (optstring[i + 1] == ':')
{
if (current[idx + 1])
{
optarg = const_cast<char*>(current + idx + 1);
optind += 1;
}
else
{
optarg = const_cast<char*>(argv[optind + 1]);
optind += 2;
}
idx = 1;
if (optind > argc)
{
if (opterr && optstring[0] != ':')
fprintf(stderr, "%s: option requires an argument -- %c\n", argv[0], optstring[i]);
optopt = optstring[i];
return optstring[0] == ':' ? ':' : '?';
}
return optstring[i];
}
else
{
if (current[++idx] == '\0')
{
idx = 1;
optind++;
}
return optstring[i];
}
}
if (opterr && optstring[0] != ':')
fprintf(stderr, "%s: illegal option -- %c\n", argv[0], current[idx]);
if (current[++idx] == '\0')
{
idx = 1;
optind++;
}
return '?';
}
pid_t getpid(void) pid_t getpid(void)
{ {
return syscall(SYS_GET_PID); return syscall(SYS_GET_PID);