X-Git-Url: http://git.tuebingen.mpg.de/?p=osl.git;a=blobdiff_plain;f=fd.c;h=b889d9d2144a4ad78cf6442997d80fec643aad87;hp=84877602f943ee5893caaaab9db93b1292ccbab8;hb=55f0ec4ba380864a06f14a7ea5793407e88def87;hpb=f065a93d3307f2065fcf8c95509166d15af4194c diff --git a/fd.c b/fd.c index 8487760..b889d9d 100644 --- a/fd.c +++ b/fd.c @@ -16,6 +16,33 @@ #include "osl.h" #include "error.h" +/** + * Wrapper for the write system call. + * + * \param fd The file descriptor to write to. + * \param buf The buffer to write. + * \param size The length of \a buf in bytes. + * + * This function writes out the given buffer and retries if an interrupt + * occurred during the write. + * + * \return On success, the number of bytes written is returned, otherwise, a + * negative error code is returned. + * + * \sa write(2). + */ +static ssize_t __write(int fd, const void *buf, size_t size) +{ + ssize_t ret; + + for (;;) { + ret = write(fd, buf, size); + if ((ret < 0) && (errno == EAGAIN || errno == EINTR)) + continue; + return ret >= 0? ret : -ERRNO_TO_ERROR(errno); + } +} + /** * Write a buffer to a file descriptor, re-write on short writes. * @@ -33,9 +60,9 @@ int write_all(int fd, const char *buf, size_t *len) assert(total); *len = 0; while (*len < total) { - int ret = write(fd, buf + *len, total - *len); - if (ret == -1) - return -ERRNO_TO_ERROR(errno); + int ret = __write(fd, buf + *len, total - *len); + if (ret < 0) + return ret; *len += ret; } return 1; @@ -64,6 +91,32 @@ int osl_open(const char *path, int flags, mode_t mode) return -ERRNO_TO_ERROR(errno); } +/** + * Open a file, write the given buffer and close the file. + * + * \param filename Full path to the file to open. + * \param buf The buffer to write to the file. + * \param size The size of \a buf. + * + * \return Standard. + */ +int write_file(const char *filename, const void *buf, size_t size) +{ + int ret, fd; + + ret = osl_open(filename, O_WRONLY | O_CREAT | O_EXCL, 0644); + if (ret < 0) + return ret; + fd = ret; + ret = write_all(fd, buf, &size); + if (ret < 0) + goto out; + ret = 1; +out: + close(fd); + return ret; +} + /** * Wrapper for chdir(2). * @@ -222,3 +275,50 @@ int osl_munmap(void *start, size_t length) strerror(err)); return -ERRNO_TO_ERROR(err); } + +/** + * Allocate a sufficiently large string and print into it. + * + * \param fmt A usual format string. + * + * Produce output according to \p fmt. No artificial bound on the length of the + * resulting string is imposed. + * + * \return This function either returns a pointer to a string that must be + * freed by the caller or \p NULL if memory allocation failed. + * + * \sa printf(3). + */ +__must_check __printf_1_2 __malloc char *make_message(const char *fmt, ...) +{ + int n; + size_t size = 100; + char *p = malloc(size); + + if (!p) + return NULL; + while (1) { + char *q; + va_list ap; + /* Try to print in the allocated space. */ + va_start(ap, fmt); + n = vsnprintf(p, size, fmt, ap); + va_end(ap); + /* If that worked, return the string. */ + if (n > -1 && n < size) + break; + /* Else try again with more space. */ + if (n > -1) /* glibc 2.1 */ + size = n + 1; /* precisely what is needed */ + else /* glibc 2.0 */ + size *= 2; /* twice the old size */ + q = realloc(p, size); + if (!q) { + free(p); + return NULL; + } + p = q; + } + return p; +} +