fd: Improve read_pattern(), rename it to read_and_compare().

[paraslash.git] / fd.c

diff --git a/fd.c b/fd.c
index d0de66f41be6008c2d3be5afe6dae002fb06ceb5..d858ae623ba6203719e70930625df97867166e67 100644 (file)
--- a/fd.c
+++ b/fd.c
@@ -260,64 +260,44 @@ int read_nonblock(int fd, void *buf, size_t sz, size_t *num_bytes)
 }
 
 /**
- * Read a buffer and check its content for a pattern.
+ * Read a buffer and compare its contents to a string, ignoring case.
  *
- * \param fd The file descriptor to receive from.
- * \param pattern The expected pattern.
- * \param bufsize The size of the internal buffer.
- *
- * This function tries to read at most \a bufsize bytes from the non-blocking
- * file descriptor \a fd. If at least \p strlen(\a pattern) bytes have been
- * received, the beginning of the received buffer is compared with \a pattern,
- * ignoring case.
+ * \param fd The file descriptor to read from.
+ * \param expectation The expected string to compare to.
  *
- * \return Positive if \a pattern was received, negative on errors, zero if no data
- * was available to read.
+ * The given file descriptor is expected to be in non-blocking mode. The string
+ * comparison is performed using strncasecmp(3).
  *
- * \sa \ref read_nonblock(), \sa strncasecmp(3).
+ * \return Zero if no data was available, positive if a buffer was read whose
+ * contents compare as equal to the expected string, negative otherwise.
+ * Possible errors: (a) not enough data was read, (b) the buffer contents
+ * compared as non-equal, (c) a read error occurred. In the first two cases,
+ * -E_READ_PATTERN is returned. In the read error case the (negative) return
+ * value of the underlying call to \ref read_nonblock() is returned.
  */
-int read_pattern(int fd, const char *pattern, size_t bufsize)
+int read_and_compare(int fd, const char *expectation)
 {
-       size_t n, len;
-       char *buf = alloc(bufsize + 1);
-       int ret = read_nonblock(fd, buf, bufsize, &n);
+       size_t n, len = strlen(expectation);
+       char *buf = alloc(len + 1);
+       int ret = read_nonblock(fd, buf, len, &n);
 
-       buf[n] = '\0';
        if (ret < 0)
                goto out;
+       buf[n] = '\0';
        ret = 0;
        if (n == 0)
                goto out;
        ret = -E_READ_PATTERN;
-       len = strlen(pattern);
        if (n < len)
                goto out;
-       if (strncasecmp(buf, pattern, len) != 0)
+       if (strncasecmp(buf, expectation, len) != 0)
                goto out;
        ret = 1;
 out:
-       if (ret < 0) {
-               PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
-               PARA_NOTICE_LOG("recvd %zu bytes: %s\n", n, buf);
-       }
        free(buf);
        return ret;
 }
 
-/**
- * Check whether a file exists.
- *
- * \param fn The file name.
- *
- * \return True iff file exists.
- */
-bool file_exists(const char *fn)
-{
-       struct stat statbuf;
-
-       return !stat(fn, &statbuf);
-}
-
 /**
  * Set a file descriptor to blocking mode.
  *
@@ -406,22 +386,6 @@ int para_open(const char *path, int flags, mode_t mode)
        return -ERRNO_TO_PARA_ERROR(errno);
 }
 
-/**
- * Wrapper for chdir(2).
- *
- * \param path The specified directory.
- *
- * \return Standard.
- */
-int para_chdir(const char *path)
-{
-       int ret = chdir(path);
-
-       if (ret >= 0)
-               return 1;
-       return -ERRNO_TO_PARA_ERROR(errno);
-}
-
 /**
  * Save the cwd and open a given directory.
  *
@@ -457,9 +421,10 @@ static int para_opendir(const char *dirname, DIR **dir, int *cwd)
                        return ret;
                *cwd = ret;
        }
-       ret = para_chdir(dirname);
-       if (ret < 0)
+       if (chdir(dirname) != 0) {
+               ret = -ERRNO_TO_PARA_ERROR(errno);
                goto close_cwd;
+       }
        *dir = opendir(".");
        if (*dir)
                return 1;
@@ -559,22 +524,21 @@ out:
  * \param start The start address of the memory mapping.
  * \param length The size of the mapping.
  *
- * \return Standard.
+ * If NULL is passed as the start address, the length value is ignored and the
+ * function does nothing.
+ *
+ * \return Zero if NULL was passed, one if the memory area was successfully
+ * unmapped, a negative error code otherwise.
  *
  * \sa munmap(2), \ref mmap_full_file().
  */
 int para_munmap(void *start, size_t length)
 {
-       int err;
-
        if (!start)
                return 0;
        if (munmap(start, length) >= 0)
                return 1;
-       err = errno;
-       PARA_ERROR_LOG("munmap (%p/%zu) failed: %s\n", start, length,
-               strerror(err));
-       return -ERRNO_TO_PARA_ERROR(err);
+       return -ERRNO_TO_PARA_ERROR(errno);
 }
 
 /**