Cygwin API Reference

Note that the core of the Single Unix Specification, Version 3 is also ISO/IEC 9945:2003 and IEEE Std 1003.1-2001 (POSIX.1-2001).

    FD_CLR
    FD_ISSET
    FD_SET
    FD_ZERO
    _Exit
    _exit
    _longjmp
    _setjmp
    _tolower
    _toupper
    a64l
    abort
    abs
    accept
    access
    acos
    acosf
    acosh
    acoshf
    alarm
    asctime
    asctime_r
    asin
    asinf
    asinh
    asinhf
    atan
    atan2
    atan2f
    atanf
    atanh
    atanhf
    atexit
    atof
    atoff
    atoi
    atol
    atoll
    basename
    bcmp
    bcopy
    bind
    bsearch
    btowc
    bzero
    cabs
    cabsf
    calloc
    catclose 			(available in external "catgets" library)
    catgets  			(available in external "catgets" library)
    catopen  			(available in external "catgets" library)
    cbrt
    cbrtf
    ceil
    ceilf
    cfgetispeed
    cfgetospeed
    cfsetispeed
    cfsetospeed
    chdir
    chmod
    chown
    chroot			(see chapter "Implementation Notes")
    clearerr
    clock
    clock_getres		(see chapter "Implementation Notes")
    clock_gettime		(see chapter "Implementation Notes")
    clock_setres		(see chapter "Implementation Notes")
    close
    closedir
    closelog
    confstr
    connect
    copysign
    copysignf
    cos
    cosf
    cosh
    coshf
    creat
    crypt			(available in external "crypt" library)
    ctermid
    ctime
    ctime_r
    daylight
    dbm_clearerr		(available in external "libgdbm" library)
    dbm_close			(available in external "libgdbm" library)
    dbm_delete			(available in external "libgdbm" library)
    dbm_error			(available in external "libgdbm" library)
    dbm_fetch			(available in external "libgdbm" library)
    dbm_firstkey		(available in external "libgdbm" library)
    dbm_nextkey			(available in external "libgdbm" library)
    dbm_open			(available in external "libgdbm" library)
    dbm_store			(available in external "libgdbm" library)
    difftime
    dirname
    div
    dlclose
    dlerror
    dlopen
    dlsym
    drand48
    dup
    dup2
    ecvt
    encrypt			(available in external "crypt" library)
    endgrent
    endhostent
    endprotoent
    endpwent
    endservent
    endutxent
    environ
    erand48
    erf
    erfc
    erfcf
    erff
    errno
    execl
    execle
    execlp
    execv
    execve
    execvp
    exit
    exp
    exp2
    exp2f
    expf
    expm1
    expm1f
    fabs
    fabsf
    fchdir
    fchmod
    fchown
    fclose
    fcntl
    fcvt
    fdatasync
    fdim
    fdimf
    fdopen
    feof
    ferror
    fflush
    ffs
    fgetc
    fgetpos
    fgets
    fileno
    flockfile
    floor
    floorf
    fma
    fmaf
    fmax
    fmaxf
    fmin
    fminf
    fmod
    fmodf
    fnmatch
    fopen
    fork
    fpathconf
    fpclassify			(see chapter "Implementation Notes")
    fprintf
    fputc
    fputs
    fread
    free
    freeaddrinfo
    freopen
    frexp
    frexpf
    fscanf
    fseek
    fseeko
    fsetpos
    fstat
    fstatvfs
    fsync
    ftell
    ftello
    ftime
    ftok
    ftruncate
    ftrylockfile
    ftw
    funlockfile
    futimes
    fwrite
    gai_strerror
    gcvt
    getaddrinfo
    getc
    getc_unlocked
    getchar
    getchar_unlocked
    getcwd
    getdelim
    getdomainname
    getegid
    getenv
    geteuid
    getgid
    getgrent
    getgrgid
    getgrgid_r
    getgrnam
    getgrnam_r
    getgroups
    gethostbyaddr
    gethostbyname
    gethostid
    gethostname
    getitimer			(see chapter "Implementation Notes")
    getlogin
    getlogin_r
    getnameinfo
    getopt
    getpeername
    getpgid
    getpgrp
    getpid
    getppid
    getpriority
    getprotobyname
    getprotobynumber
    getprotoent
    getpwent
    getpwnam
    getpwnam_r
    getpwuid
    getpwuid_r
    getrlimit
    getrusage
    gets
    getservbyname
    getservbyport
    getservent
    getsid
    getsockname
    getsockopt
    getsubopt
    gettimeofday
    getuid
    getutxent
    getutxid
    getutxline
    getwd
    glob
    globfree
    gmtime
    gmtime_r
    grantpt
    h_errno
    hcreate
    hdestroy
    hsearch
    hstrerror
    htonl
    htons
    hypot
    hypotf
    iconv			(available in external "libiconv" library)
    iconv_close			(available in external "libiconv" library)
    iconv_open			(available in external "libiconv" library)
    if_freenameindex
    if_indextoname
    if_nameindex
    if_nametoindex
    ilogb
    ilogbf
    imaxabs
    imaxdiv
    index
    inet_addr
    inet_ntoa
    inet_ntop
    inet_pton
    initstate
    insque
    ioctl
    isalnum
    isalpha
    isascii
    isatty
    isblank
    iscntrl
    isdigit
    isfinite			(see chapter "Implementation Notes")
    isgraph
    isgreater			(see chapter "Implementation Notes")
    isgreaterequal		(see chapter "Implementation Notes")
    isinf			(see chapter "Implementation Notes")
    isless
    islessequal			(see chapter "Implementation Notes")
    islessgreater		(see chapter "Implementation Notes")
    islower
    isnan			(see chapter "Implementation Notes")
    isnormal			(see chapter "Implementation Notes")
    isprint
    ispunct
    isspace
    isunordered			(see chapter "Implementation Notes")
    isupper
    iswalnum
    iswalpha
    iswblank
    iswcntrl
    iswctype
    iswdigit
    iswgraph
    iswlower
    iswprint
    iswpunct
    iswspace
    iswupper
    iswxdigit
    isxdigit
    j0
    j1
    jn
    jrand48
    kill
    killpg
    l64a
    labs
    lchown
    lcong48
    ldexp
    ldexpf
    ldiv
    lfind
    lgamma
    lgammaf
    link
    listen
    llabs
    lldiv
    llrint
    llrintf
    llrintl
    localeconv
    localtime
    localtime_r
    lockf
    log
    log10
    log10f
    log1p
    log1pf
    logb
    logbf
    logf
    longjmp
    lrand48
    lrint
    lrintf
    lrintl
    lround
    lroundf
    lsearch
    lseek
    lstat
    malloc
    mblen
    mbrlen
    mbrtowc
    mbsinit
    mbsrtowcs
    mbstowcs
    mbtowc
    memccpy
    memchr
    memcmp
    memcpy
    memmove
    memset
    mkdir
    mkfifo
    mknod
    mkstemp
    mktemp
    mktime
    mlock
    mmap
    modf
    modff
    mprotect
    mq_close
    mq_getattr
    mq_notify
    mq_open
    mq_receive
    mq_send
    mq_setattr
    mq_timedreceive
    mq_timedsend
    mq_unlink
    mrand48
    msgctl			(see chapter "Implementation Notes")
    msgget			(see chapter "Implementation Notes")
    msgrcv			(see chapter "Implementation Notes")
    msgsnd			(see chapter "Implementation Notes")
    msync
    munlock
    munmap
    nan
    nanf
    nanosleep
    nearbyint
    nearbyintf
    nextafter
    nextafterf
    nftw
    nice
    nl_langinfo
    nrand48
    ntohl
    ntohs
    open
    opendir
    openlog
    optarg
    opterr
    optind
    optopt
    pathconf
    pause
    pclose
    perror
    pipe
    poll
    popen
    posix_fadvise
    posix_fallocate
    posix_madvise
    posix_memalign
    posix_openpt
    pow
    powf
    pread
    printf
    pselect
    pthread_atfork
    pthread_attr_destroy
    pthread_attr_getdetachstate
    pthread_attr_getinheritsched
    pthread_attr_getschedparam
    pthread_attr_getschedpolicy
    pthread_attr_getscope
    pthread_attr_getstacksize
    pthread_attr_init
    pthread_attr_setdetachstate
    pthread_attr_setinheritsched
    pthread_attr_setschedparam
    pthread_attr_setschedpolicy
    pthread_attr_setscope
    pthread_attr_setstacksize
    pthread_cancel
    pthread_cond_broadcast
    pthread_cond_destroy
    pthread_cond_init
    pthread_cond_signal
    pthread_cond_timedwait
    pthread_cond_wait
    pthread_condattr_destroy
    pthread_condattr_getpshared
    pthread_condattr_init
    pthread_condattr_setpshared
    pthread_create
    pthread_detach
    pthread_equal
    pthread_exit
    pthread_getconcurrency
    pthread_getschedparam
    pthread_getspecific
    pthread_join
    pthread_key_create
    pthread_key_delete
    pthread_kill
    pthread_mutex_destroy
    pthread_mutex_getprioceiling
    pthread_mutex_init
    pthread_mutex_lock
    pthread_mutex_setprioceiling
    pthread_mutex_trylock
    pthread_mutex_unlock
    pthread_mutexattr_destroy
    pthread_mutexattr_getprioceiling
    pthread_mutexattr_getprotocol
    pthread_mutexattr_getpshared
    pthread_mutexattr_gettype
    pthread_mutexattr_init
    pthread_mutexattr_setprioceiling
    pthread_mutexattr_setprotocol
    pthread_mutexattr_setpshared
    pthread_mutexattr_settype
    pthread_once
    pthread_rwlock_destroy
    pthread_rwlock_init
    pthread_rwlock_rdlock
    pthread_rwlock_tryrdlock
    pthread_rwlock_trywrlock
    pthread_rwlock_unlock
    pthread_rwlock_wrlock
    pthread_rwlockattr_destroy
    pthread_rwlockattr_getpshared
    pthread_rwlockattr_init
    pthread_rwlockattr_setpshared
    pthread_self
    pthread_setcancelstate
    pthread_setcanceltype
    pthread_setconcurrency
    pthread_setschedparam
    pthread_setspecific
    pthread_sigmask
    pthread_testcancel
    ptsname
    putc
    putc_unlocked
    putchar
    putchar_unlocked
    putenv
    puts
    pututxline
    pwrite
    qsort
    raise
    rand
    rand_r
    random
    read
    readdir
    readdir_r
    readlink
    readv
    realloc
    realpath
    recv
    recvfrom
    recvmsg
    regcomp
    regerror
    regexec
    regfree
    remainder
    remainderf
    remove
    remque
    remquo
    remquof
    rename
    rewind
    rewinddir
    rindex
    rint
    rintf
    rintl
    rmdir
    round
    roundf
    scalb
    scalbln
    scalblnf
    scalbn
    scalbnf
    scandir
    scanf
    sched_get_priority_max
    sched_get_priority_min
    sched_getparam
    sched_getscheduler
    sched_rr_get_interval
    sched_setparam
    sched_setscheduler
    sched_yield
    seed48
    seekdir
    select
    sem_close
    sem_destroy
    sem_getvalue
    sem_init
    sem_open
    sem_post
    sem_timedwait
    sem_trywait
    sem_unlink
    sem_wait
    semctl			(see chapter "Implementation Notes")
    semget			(see chapter "Implementation Notes")
    semop			(see chapter "Implementation Notes")
    send
    sendmsg
    sendto
    setbuf
    setegid
    setenv
    seteuid
    setgid
    setgrent
    sethostent
    setitimer			(see chapter "Implementation Notes")
    setjmp
    setkey			(available in external "crypt" library)
    setlocale
    setlogmask
    setpgid
    setpgrp
    setpriority
    setprotoent
    setpwent
    setregid
    setreuid
    setrlimit
    setservent
    setsid
    setsockopt
    setstate
    setuid
    setutxent
    setvbuf
    shm_open
    shm_unlink
    shmat			(see chapter "Implementation Notes")
    shmctl			(see chapter "Implementation Notes")
    shmdt			(see chapter "Implementation Notes")
    shmget			(see chapter "Implementation Notes")
    shutdown
    sigaction
    sigaddset
    sigdelset
    sigemptyset
    sigfillset
    sighold
    sigignore
    siginterrupt
    sigismember
    siglongjmp
    signal
    signbit			(see chapter "Implementation Notes")
    signgam
    sigpause
    sigpending
    sigprocmask
    sigqueue
    sigrelse
    sigset
    sigsetjmp
    sigsuspend
    sigwait
    sigwaitinfo
    sin
    sinf
    sinh
    sinhf
    sleep
    snprintf
    socket
    socketpair
    sprintf
    sqrt
    sqrtf
    srand
    srand48
    srandom
    sscanf
    stat
    statvfs
    stderr
    stdin
    stdout
    strcasecmp
    strcat
    strchr
    strcmp
    strcoll
    strcpy
    strcspn
    strdup
    strerror
    strerror_r
    strftime
    strlen
    strncasecmp
    strncat
    strncmp
    strncpy
    strpbrk
    strptime
    strrchr
    strspn
    strstr
    strtod
    strtof
    strtoimax
    strtok
    strtok_r
    strtol
    strtoll
    strtoul
    strtoull
    strtoumax
    strxfrm
    swab
    symlink
    sync
    sysconf
    syslog
    system
    tan
    tanf
    tanh
    tanhf
    tcdrain
    tcflow
    tcflush
    tcgetattr
    tcgetpgrp
    tcsendbreak
    tcsetattr
    tcsetpgrp
    tdelete
    telldir
    tempnam
    tfind
    tgamma
    tgammaf
    time
    timer_create
    timer_delete
    timer_gettime
    timer_settime
    times
    timezone
    tmpfile
    tmpnam
    toascii
    tolower
    toupper
    towctrans
    towlower
    towupper
    trunc
    truncate
    truncf
    tsearch
    ttyname
    ttyname_r
    twalk
    tzname
    tzset
    ualarm
    umask
    uname
    ungetc
    unlink
    unlockpt
    unsetenv
    usleep
    utime
    utimes
    va_arg
    va_copy
    va_end
    va_start
    vfork			(see chapter "Implementation Notes")
    vfprintf
    vfscanf
    vprintf
    vscanf
    vsnprintf
    vsprintf
    vsscanf
    wait
    waitpid
    wcrtomb
    wcscat
    wcschr
    wcscmp
    wcscoll
    wcscpy
    wcscspn
    wcslen
    wcsncat
    wcsncmp
    wcsncpy
    wcspbrk
    wcsrchr
    wcsrtombs
    wcsspn
    wcsstr
    wcstol
    wcstoll
    wcstombs
    wcstoul
    wcstoull
    wcswidth
    wcsxfrm
    wctob
    wctomb
    wctrans
    wctype
    wcwidth
    wmemchr
    wmemcmp
    wmemcpy
    wmemmove
    wmemset
    wprintf
    write
    writev
    y0
    y1
    yn

    alphasort
    bindresvport
    bindresvport_sa
    cfmakeraw
    daemon
    dn_comp
    dn_expand
    dn_skipname
    drem
    endusershell
    err
    errx
    finite
    finitef
    fiprintf
    flock
    forkpty
    freeifaddrs
    fstatfs
    fts_children
    fts_close
    fts_get_clientptr
    fts_get_stream
    fts_open
    fts_read
    fts_set
    fts_set_clientptr
    funopen
    gamma
    gamma_r
    gammaf
    gammaf_r
    getdtablesize
    getifaddrs
    getpagesize
    getpeereid
    getprogname
    getusershell
    herror
    inet_aton
    inet_makeaddr
    inet_netof
    inet_network
    initgroups
    iruserok
    iruserok_sa
    login
    login_tty
    logout
    logwtmp
    mkdtemp
    openpty
    rcmd
    rcmd_af
    res_close
    res_init
    res_mkquery
    res_nclose
    res_ninit
    res_nmkquery
    res_nquery
    res_nquerydomain
    res_nsearch
    res_nsend
    res_query
    res_querydomain
    res_search
    res_send
    revoke
    rexec
    rresvport
    rresvport_af
    ruserok
    sbrk
    setbuffer
    setgroups
    setlinebuf
    setpassent
    setprogname
    settimeofday
    setusershell
    statfs
    strcasestr
    strlcat
    strlcpy
    strsep
    strsignal
    updwtmp
    valloc
    verr
    verrx
    vhangup			(see chapter "Implementation Notes")
    vsyslog
    vwarn
    vwarnx
    wait3
    wait4
    warn
    warnx
    wcslcat
    wcslcpy

    argz_add
    argz_add_sep
    argz_append
    argz_count
    argz_create
    argz_create_sep
    argz_delete
    argz_extract
    argz_insert
    argz_next
    argz_replace
    argz_stringify
    asnprintf
    asprintf
    asprintf_r
    dprintf
    dremf
    envz_add
    envz_entry
    envz_get
    envz_merge
    envz_remove
    envz_strip
    exp10
    exp10f
    fcloseall
    fcloseall_r
    fgetxattr
    flistxattr
    fmemopen
    fopencookie
    fremovexattr
    fsetxattr
    getline
    getopt_long
    getopt_long_only
    getxattr
    lgetxattr
    listxattr
    llistxattr
    lremovexattr
    lsetxattr
    memmem
    mempcpy
    open_memstream
    pow10
    pow10f
    removexattr
    setxattr
    stpcpy
    stpncpy
    strndup
    strnlen
    tdestroy
    timegm
    timelocal
    updwtmpx
    utmpxname
    vasnprintf
    vasprintf
    vasprintf_r
    vdprintf
    wcpcpy
    wcpncpy

    acl
    aclcheck
    aclfrommode
    aclfrompbits
    aclfromtext
    aclsort
    acltomode
    acltopbits
    acltotext
    endmntent
    faccessat
    facl
    fchmodat
    fchownat
    fdopendir
    fstatat
    futimesat
    getmntent
    linkat
    memalign
    mkdirat
    mkfifoat
    mknodat
    openat
    readlinkat
    renameat
    setmntent
    symlinkat
    unlinkat

    futimens
    utimensat

    cuserid			(POSIX.1-1988, SUSv2)
    endutent			(XPG2)
    getpass			(SUSv2)
    getutent			(XPG2)
    getutid			(XPG2)
    getutline			(XPG2)
    getw			(SVID)
    mallinfo			(SVID)
    mallopt			(SVID)
    on_exit			(SunOS)
    pthread_continue		(XPG2)
    pthread_getsequence_np	(Tru64)
    pthread_suspend		(XPG2)
    pututline			(XPG2)
    putw			(SVID)
    setutent			(XPG2)
    sys_errlist			(BSD)
    sys_nerr			(BSD)
    ttyslot			(SUSv2)
    utmpname			(XPG2)

    acoshl
    acosl
    aio_cancel
    aio_error
    aio_fsync
    aio_read
    aio_return
    aio_suspend
    aio_write
    asinhl
    asinl
    atan2l
    atanhl
    atanl
    bsd_signal
    cabsl
    cacos
    cacosf
    cacosh
    cacoshf
    cacoshl
    cacosl
    carg
    cargf
    cargl
    casin
    casinf
    casinh
    casinhf
    casinhl
    casinl
    catan
    catanf
    catanh
    catanhf
    catanhl
    catanl
    cbrtl
    ccos
    ccosf
    ccosh
    ccoshf
    ccoshl
    ccosl
    ceill
    cexp
    cexpf
    cexpl
    cimag
    cimagf
    cimagl
    clock_getcpuclockid
    clog
    clogf
    clogl
    conj
    conjf
    conjl
    copysignl
    coshl
    cosl
    cpow
    cpowf
    cpowl
    cproj
    cprojf
    cprojl
    creal
    crealf
    creall
    csin
    csinf
    csinh
    csinhf
    csinhl
    csinl
    csqrt
    csqrtf
    csqrtl
    ctan
    ctanf
    ctanh
    ctanhf
    ctanhl
    ctanl
    endnetent
    erfcl
    erfl
    exp2l
    expl
    expm1l
    fabsl
    fattach
    fdiml
    feclearexcept
    fegetenv
    fegetexceptflag
    fegetround
    feholdexcept
    feraiseexcept
    fesetenv
    fesetexceptflag
    fesetround
    fetestexcept
    feupdateenv
    fgetwc
    fgetws
    floorl
    fmal
    fmaxl
    fminl
    fmodl
    fmtmsg
    fputwc
    fputws
    frexpl
    fwide
    fwprintf
    fwscanf
    getcontext
    getdate
    getdate_err
    gethostent
    getmsg
    getnetbyaddr
    getnetbyname
    getnetent
    getpmsg
    getwc
    getwchar
    hypotl
    ilogbl
    initstate
    isastream
    ldexpl
    lgammal
    lio_listio
    llround
    llroundf
    llroundl
    log10l
    log1pl
    log2l
    logbl
    logl
    lroundl
    makecontext
    mlockall
    modfl
    munlockall
    nanl
    nearbyintl
    nextafterl
    nexttowardl
    posix_mem_offset
    posix_spawn[...]
    posix_trace[...]
    posix_typed_[...]
    powl
    pthread_attr_getguardsize
    pthread_attr_getstack
    pthread_attr_getstackaddr
    pthread_attr_setguardsize
    pthread_attr_setstack
    pthread_attr_setstackaddr
    pthread_barrier[...]
    pthread_condattr_getclock
    pthread_condattr_setclock
    pthread_getcpuclockid
    pthread_mutex_timedlock
    pthread_rwlock_timedrdlock
    pthread_rwlock_timedwrlock
    pthread_setschedprio
    pthread_spin_[...]
    putmsg
    reminderl
    remquol
    roundl
    scalblnl
    scalbnl
    setcontext
    setnetent
    sigaltstack
    sigtimedwait
    sinhl
    sinl
    sockatmark
    sqrtl
    strfmon
    strtold
    swabcontext
    swprintf
    swscanf
    tanhl
    tanl
    tcgetsid
    tgammal
    timer_getoverrun
    truncl
    ulimit
    vfwprintf
    vfwscanf
    vswprintf
    vswscanf
    vwprintf
    vwscanf
    waitid
    wcsftime
    wcstod
    wcstof
    wcstoimax
    wcstok
    wcstold
    wcstoumax
    wcswcs
    wordexp
    wordfree
    wscanf

chroot only emulates a chroot function call by keeping track of the current root and accomodating this in the file related function calls. A real chroot functionality is not supported by Windows however.

clock_getres, clock_gettime and clock_setres only support CLOCK_REALTIME for now.

fpclassify, isfinite, isgreater, isgreaterequal, isinf, isless, islessequal, islessgreater, isnan, isnormal, isunordered, and signbit only support float and double arguments, not long double arguments.

getitimer and setitimer only support ITIMER_REAL for now.

link will copy the file if it can't implement a true hardlink. This is true at least for FAT and FAT32 filesystems. NTFS supports hardlinks.

lseek only works properly on binary files.

setuid is only safe against reverting the user switch after a call to one of the exec(2) functions took place. Windows doesn't support a non-revertable user switch within the context of Win32 processes.

vfork just calls fork.

vhangup always returns -1 and sets errno to ENOSYS.

The XSI IPC functions semctl, semget, semop, shmat, shmctl, shmdt, shmget, msgctl, msgget, msgrcv and msgsnd are only available when cygserver is running and the CYGWIN environment variable is set so that it contains the string server.

This function can be used to turn a Win32 "handle" into a posix-style file handle. fd may be -1 to make cygwin allocate a handle; the actual handle is returned in all cases.

Use this function to convert POSIX paths in from to Win32 paths in to or, vice versa, Win32 paths in from to POSIX paths in to. what defines the direction of this conversion and can be any of the below values.

  CCP_POSIX_TO_WIN_A      /* from is char *posix, to is char *win32       */
  CCP_POSIX_TO_WIN_W,     /* from is char *posix, to is wchar_t *win32    */
  CCP_WIN_A_TO_POSIX,     /* from is char *win32, to is char *posix       */
  CCP_WIN_W_TO_POSIX,     /* from is wchar_t *win32, to is char *posix    */

You can additionally or the following values to what, to define whether you want the resulting path in to to be absolute or if you want to keep relative paths in relative notation. Creating absolute paths is the default.

  CCP_ABSOLUTE = 0,       /* Request absolute path (default).             */
  CCP_RELATIVE = 0x100    /* Request to keep path relative.               */

If size is 0, cygwin_conv_path just returns the required buffer size in bytes. Otherwise, it returns 0 on success, or -1 on error and errno is set to one of the below values.

    EINVAL        what has an invalid value.
    EFAULT        from or to point into nirvana.
    ENAMETOOLONG  the resulting path is longer than 32K, or, in case
                  of what == CCP_POSIX_TO_WIN_A, longer than MAX_PATH.
    ENOSPC        size is less than required for the conversion.

#include <sys/cygwin.h>

/* Conversion from incoming Win32 path given as wchar_t *win32 to POSIX path.
   If incoming path is a relative path, stick to it.  First ask how big
   the output buffer has to be and allocate space dynamically. */
ssize_t size;
char *posix;
size = cygwin_conv_path (CCP_WIN_W_TO_POSIX | CCP_RELATIVE, win32, NULL, 0);
if (size < 0)
  perror ("cygwin_conv_path");
else
  {
    posix = (char *) malloc (size);
    if (cygwin_conv_path (CCP_WIN_W_TO_POSIX | CCP_RELATIVE, win32,
                          posix, size))
      perror ("cygwin_conv_path");
  }

This is the same as cygwin_conv_path, but the input is treated as a path list in $PATH or %PATH% notation.

If what is CCP_POSIX_TO_WIN_A or CCP_POSIX_TO_WIN_W, given a POSIX $PATH-style string (i.e. /foo:/bar) convert it to the equivalent Win32 %PATH%-style string (i.e. d:\;e:\bar).

If what is CCP_WIN_A_TO_POSIX or CCP_WIN_W_TO_POSIX, given a Win32 %PATH%-style string (i.e. d:\;e:\bar) convert it to the equivalent POSIX $PATH-style string (i.e. /foo:/bar).

See also cygwin_conv_path

This is equivalent to the cygwin_conv_path, except that cygwin_create_path does not take a buffer pointer for the result of the conversion as input. Rather it allocates the buffer itself using malloc(3) and returns a pointer to this buffer. In case of error it returns NULL and sets errno to one of the values defined for cygwin_conv_path. Additionally errno can be set to the below value.

    ENOMEM        Insufficient memory was available.

When you don't need the returned buffer anymore, use free(3) to deallocate it.

See also cygwin_conv_path

This function gives you access to various internal data and functions. It takes two arguments. The first argument is a type from the 'cygwin_getinfo_types' enum. The second is an optional pointer.

Stay away unless you know what you're doing.

Given a pointer ot a passwd entry of a user and a cleartext password, returns a HANDLE to an impersonation token for this user which can be used in a subsequent call to cygwin_set_impersonation_token to impersonate that user. This function can only be called from a process which has the required NT user rights to perform a logon.

See also the chapter "New setuid concept" in the Cygwin user's guide.

See also cygwin_set_impersonation_token

This function tells you if the supplied path is a POSIX-style path (i.e. posix names, forward slashes, colon delimiters) or a Win32-style path (drive letters, reverse slashes, semicolon delimiters. The return value is true if the path is a POSIX path. Note that "_p" means "predicate", a lisp term meaning that the function tells you something about the parameter.

Rather than use a mode to say what the "proper" path list format is, we allow any, and give apps the tools they need to convert between the two. If a ';' is present in the path list it's a Win32 path list. Otherwise, if the first path begins with [letter]: (in which case it can be the only element since if it wasn't a ';' would be present) it's a Win32 path list. Otherwise, it's a POSIX path list.

Use this function to enable the token given as parameter as impersonation token for the next call to setuid or seteuid. Use cygwin_set_impersonation_token together with cygwin_logon_user to impersonate users using password authentication.

See also the chapter "New setuid concept" in the Cygwin user's guide.

See also cygwin_logon_user

Split a path into the directory and the file portions. Both dir and file are expected to point to buffers of sufficient size.

char dir[200], file[100];
cygwin_split_path("c:/foo/bar.c", dir, file);
printf("dir=%s, file=%s\n", dir, file);

Outputs a stackdump to stderr from the called location.

Given a windows pid, converts to the corresponding Cygwin pid, if any. Returns -1 if windows pid does not correspond to a cygwin pid.

      extern "C" cygwin_winpid_to_pid (int winpid);
      pid_t mypid;
      mypid = cygwin_winpid_to_pid (windows_pid);