Cygwin API Reference

clearerr, fclose, feof, ferror, fflush, fgetc, fgetpos, fgets, fopen, fprintf, fputc, fputs, fread, freopen, fscanf, fseek, fsetpos, ftell, fwrite, getc, getchar, gets, perror, printf, putc, putchar, puts, remove, rename, rewind, scanf, setbuf, setvbuf, sprintf, sscanf, tmpfile, tmpnam, vfprintf, ungetc, vprintf, vsprintf,

memchr, memcmp, memcpy, memmove, memset, strcat, strchr, strcmp, strcoll, strcpy, strcspn, strerror, strlen, strncat, strncmp, strncpy, strpbrk, strrchr, strspn, strstr, strtok, strxfrm

abort, abs, assert, atexit, atof, atoi, atol, bsearch, calloc, div, exit, free, getenv, labs, ldiv, longjmp, malloc, mblen, mbstowcs, mbtowc, qsort, rand, realloc, setjmp, srand, strtod, strtol, strtoul, system, wcstombs, wctomb

asctime, gmtime, localtime, time, clock, ctime, difftime, mktime, strftime

raise, signal

isalnum, isalpha, iscntrl, isdigit, isgraph, islower, isprint, ispunct, isspace, isupper, isxdigit, tolower, toupper

acos, asin, atan, atan2, ceil, cos, cosh, exp, fabs, floor, fmod, frexp, ldexp, log, log10, modf, pow, sin, sinh, sqrt, tan, tanh

localeconv, setlocale, va_arg, va_end, va_start

fork, execl, execle, execlp, execv, execve, execvp, wait, waitpid, _exit, kill, sigemptyset, sigfillset, sigaddset, sigdelset, sigismember, sigaction, pthread_sigmask, sigprocmask, sigpending, sigsuspend, alarm, pause, sleep, pthread_kill, pthread_sigmask

getpid, getppid, getuid, geteuid, getgid, getegid, setuid, setgid, getgroups, getlogin, getpgrp, setsid, setpgid, uname, time, times, getenv, ctermid, ttyname, isatty, sysconf

opendir, readdir, rewinddir, closedir, chdir, getcwd, open, creat, umask, link, mkdir, unlink, rmdir, rename, stat, fstat, access, chmod, fchmod, chown, utime, ftruncate, pathconf, fpathconf

pipe, dup, dup2, close, read, write, fcntl, lseek, fsync

cfgetispeed, cfgetospeed, cfsetispeed, cfsetospeed, tcdrain, tcflow, tcflush, tcgetattr, tcgetpgrp, tcsendbreak, tcsetattr, tcsetpgrp

abort, exit, fclose, fdopen, fflush, fgetc, fgets, fileno, fopen, fprintf, fputc, fputs, fread, freopen, fscanf, fseek, ftell, fwrite, getc, getchar, gets, perror, printf, putc, putchar, puts, remove, rewind, scanf, setlocale, siglongjmp, sigsetjmp, tmpfile, tmpnam, tzset

getgrgid, getgrnam, getpwnam, getpwuid

sem_init, sem_destroy, sem_wait, sem_trywait, sem_post, pthread_mutex_init, pthread_mutex_destroy, pthread_mutex_lock, pthread_mutex_trylock, pthread_mutex_unlock

mmap, mprotect, msync, munmap

pthread_attr_init, pthread_attr_destroy, pthread_attr_setstacksize, pthread_attr_getstacksize, pthread_create, pthread_exit, pthread_self, pthread_equal

pthread_key_create, pthread_setspecific, pthread_getspecific, pthread_key_delete

setuid and setgid always return ENOSYS.

link will copy the file if it can't implement a true symbolic link. Currently, symbolic links work, if at all, only under Windows NT.

chown always returns zero.

fcntl doesn't support F_GETLK - it returns -1 and sets errno to ENOSYS.

lseek only works properly on binary files.

(Standardized by POSIX 1.g, which is probably still in draft?)

accept, bind, connect, getdomainname, gethostbyaddr, gethostbyname, getpeername, getprotobyname, getprotobynumber, getservbyname, getservbyport, getsockname, getsockopt, herror, htonl, htons, inet_addr, inet_makeaddr, inet_netof, inet_ntoa, listen, ntohl, ntohs, rcmd, recv, recvfrom, rexec, rresvport, send, sendto, setsockopt, shutdown, socket, socketpair

Of these networking calls, rexec, rcmd and rresvport are implemented in MS IP stack but may not be implemented in other vendors' stacks.

chroot, closelog, cwait, dlclose, dlerror, dlfork, dlopen, dlsym, endgrent, ffs, fstatfs, ftime, get_osfhandle, getdtablesize, getgrent, gethostname, getitimer, getmntent, getpagesize, getpgid, getpwent, gettimeofday, grantpt, initgroups, ioctl, killpg, login, logout, lstat, mknod, memccpy, nice, openlog, pclose, popen, ptsname, putenv, random, readv, realpath, regfree, rexec, select, setegid setenv, seterrno, seteuid, setitimer, setmntent, setmode, setpassent, setpgrp, setpwent, settimeofday, sexecl, sexecle, sexeclp, sexeclpe, sexeclpe, sexecp, sexecv, sexecve, sexecvpe, sigpause, spawnl, spawnle, spawnlp, spawnlpe, spawnv, spawnve, spawnvp, spawnvpe, srandom, statfs, strsignal, strtosigno, swab, syslog, timezone, truncate, ttyslot, unlockpt, unsetenv, usleep, utimes, vfork, vhangup, wait3, wait4, wcscmp, wcslen, wprintf, writev

initgroups does nothing

chroot, mknod, settimeofday, and vhangup always return -1 and sets errno to ENOSYS.

nice allows Cygwin programs to alter their current runtime priority through the use of its incr argument. Cygwin processes can be set to IDLE_PRIORITY_CLASS, NORMAL_PRIORITY_CLASS, HIGH_PRIORITY_CLASS, or REALTIME_PRIORITY_CLASS with the nice call. NORMAL_PRIORITY_CLASS is the default. If you pass a positive number to nice(), then the priority level will decrease by one (within the above list of priorities). A negative number would make it increase by one. It is not possible to change it by more than one at a time without making repeated calls. An increment above REALTIME_PRIORITY_CLASS results in the process staying at that priority. Likewise, a decrement to IDLE_PRIORITY_CLASS has it stay at that priority. Note that in the Win32 API, there are 32 priorities. So currently we only give access to four of these through nice.

seteuid and setegid always return 0 and set errno to ENOSYS.

vfork just calls fork