Codice

392 volume VI os16
Sorgenti della libreria generale 393
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4030019 |}
105.17.28 lib/unistd/read.c
Si veda la sezione 97.29.
4040001 |#include
4040002 |#include
4040003 |#include
4040004 |#include
4040005 |#include
4040006 |//----------------------------------------------------------------------
4040007 |ssize_t
4040008 |read (int fdn, void *buffer, size_t count)
4040009 |{
4040010 | sysmsg_read_t msg;
4040011 | //
4040012 | // Reduce size of read if necessary.
4040013 | //
4040014 | if (count > BUFSIZ)
4040015 | {
4040016 | count = BUFSIZ;
4040017 | }
4040018 | //
4040019 | // Fill the message.
4040020 | //
4040021 | msg.fdn = fdn;
4040022 | msg.count = count;
4040023 | msg.eof = 0;
4040024 | msg.ret = 0;
4040025 | //
4040026 | // Repeat syscall, until something is received or end of file is
4040027 | // reached.
4040028 | //
4040029 | while (1)
4040030 | {
4040031 | sys (SYS_READ, &msg, (sizeof msg));
4040032 | if (msg.ret != 0 || msg.eof)
4040033 | {
4040034 | break;
4040035 | }
4040036 | }
4040037 | //
4040038 | // Before return: be careful with the ‘msg.buffer’ copy, because
4040039 | // it cannot be longer than ‘count’, otherwise, some unexpected
4040040 | // memory will be overwritten!
4040041 | //
4040042 | if (msg.ret < 0)
4040043 | {
4040044 | //
4040045 | // No valid read, no change inside the buffer.
4040046 | //
4040047 | errno = msg.errno;
4040048 | return (msg.ret);
4040049 | }
4040050 | //
4040051 | if (msg.ret > count)
4040052 | {
4040053 | //
4040054 | // A strange value was returned. Considering it a read error.
4040055 | //
4040056 | errset (EIO); // I/O error.
4040057 | return (-1);
4040058 | }
4040059 | //
4040060 | // A valid read: fill the buffer with ‘msg.ret’ bytes.
4040061 | //
4040062 | memcpy (buffer, msg.buffer, msg.ret);
4040063 | //
4040064 | // Return.
4040065 | //
4040066 | return (msg.ret);
4040067 |}
105.17.29 lib/unistd/rmdir.c
Si veda la sezione 97.30.
4050001 |#include
4050002 |#include
4050003 |#include
4050004 |#include
4050005 |#include
4050006 |#include
4050007 |//----------------------------------------------------------------------
4050008 |int
4050009 |rmdir (const char *path)
4050010 |{
4050011 | sysmsg_stat_t msg_stat;
4050012 | sysmsg_unlink_t msg_unlink;
4050013 | //
4050014 | if (path == NULL)
4050015 | {
4050016 | errset (EINVAL);
4050017 | return (-1);
4050018 | }
4050019 | //
4050020 | strncpy (msg_stat.path, path, PATH_MAX);
4050021 | //
4050022 | sys (SYS_STAT, &msg_stat, (sizeof msg_stat));
4050023 | //
4050024 | if (msg_stat.ret != 0)
4050025 | {
4050026 | errno = msg_stat.errno;
4050027 | errln = msg_stat.errln;
4050028 | strncpy (errfn, msg_stat.errfn, PATH_MAX);
4050029 | return (msg_stat.ret);
4050030 | }
4050031 | //
4050032 | if (!S_ISDIR (msg_stat.stat.st_mode))
4050033 | {
4050034 | errset (ENOTDIR); // Not a directory.
4050035 | return (-1);
4050036 | }
4050037 | //
4050038 | strncpy (msg_unlink.path, path, PATH_MAX);
4050039 | //
4050040 | sys (SYS_UNLINK, &msg_unlink, (sizeof msg_unlink));
4050041 | //
4050042 | errno = msg_unlink.errno;
4050043 | errln = msg_unlink.errln;
4050044 | strncpy (errfn, msg_unlink.errfn, PATH_MAX);
4050045 | return (msg_unlink.ret);
4050046 |}
105.17.30 lib/unistd/seteuid.c
Si veda la sezione 97.33.
4060001 |#include
4060002 |#include
4060003 |#include
4060004 |#include
4060005 |#include
4060006 |//----------------------------------------------------------------------
4060007 |int
4060008 |seteuid (uid_t uid)
4060009 |{
4060010 | sysmsg_seteuid_t msg;
4060011 | msg.ret = 0;
4060012 | msg.errno = 0;
4060013 | msg.euid = uid;
4060014 | sys (SYS_SETEUID, &msg, (sizeof msg));
4060015 | errno = msg.errno;
4060016 | errln = msg.errln;
4060017 | strncpy (errfn, msg.errfn, PATH_MAX);
4060018 | return (msg.ret);
4060019 |}
4060020 |
105.17.31 lib/unistd/setpgrp.c
Si veda la sezione 97.32.
4070001 |#include
4070002 |#include
4070003 |#include
4070004 |//----------------------------------------------------------------------
4070005 |int
4070006 |setpgrp (void)
4070007 |{
4070008 | sys (SYS_PGRP, NULL, (size_t) 0);
4070009 | return (0);
4070010 |}
105.17.32 lib/unistd/setuid.c
Si veda la sezione 97.33.
4080001 |#include
4080002 |#include
4080003 |#include
4080004 |#include
4080005 |#include
4080006 |//----------------------------------------------------------------------
4080007 |int
4080008 |setuid (uid_t uid)
4080009 |{
4080010 | sysmsg_setuid_t msg;
4080011 | msg.ret = 0;
4080012 | msg.errno = 0;
4080013 | msg.euid = uid;
4080014 | sys (SYS_SETUID, &msg, (sizeof msg));
4080015 | errno = msg.errno;
4080016 | errln = msg.errln;
4080017 | strncpy (errfn, msg.errfn, PATH_MAX);
4080018 | return (msg.ret);
4080019 |}
105.17.33 lib/unistd/sleep.c
Si veda la sezione 97.35.
4090001 |#include
4090002 |#include
4090003 |#include
4090004 |#include
4090005 |#include
4090006 |//----------------------------------------------------------------------
4090007 |unsigned int
4090008 |sleep (unsigned int seconds)
4090009 |{
4090010 | sysmsg_sleep_t msg;
4090011 | time_t start;
4090012 | time_t end;
4090013 | int slept;
4090014 | //
4090015 | if (seconds == 0)
4090016 | {
4090017 | return (0);
4090018 | }
4090019 | //
4090020 | msg.events = WAKEUP_EVENT_TIMER;
4090021 | msg.seconds = seconds;
4090022 | sys (SYS_SLEEP, &msg, (sizeof msg));
4090023 | start = msg.ret;
4090024 | end = time (NULL);
4090025 | slept = end - msg.ret;
4090026 | //
4090027 | if (slept < 0)
4090028 | {
4090029 | return (seconds);
4090030 | }
4090031 | else if (slept < seconds)
4090032 | {
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