find: fix build failure on certain configs

[oweals/busybox.git] / libbb / read.c

diff --git a/libbb/read.c b/libbb/read.c
index 50e0354add44c983177511c1ce365e3c242b98e7..502d407c410d824ca58c6fd43d30975a6c890a8e 100644 (file)
--- a/libbb/read.c
+++ b/libbb/read.c
@@ -38,10 +38,8 @@ ssize_t full_read(int fd, void *buf, size_t len)
 
                if (cc < 0)
                        return cc;      /* read() returns -1 on failure. */
-
                if (cc == 0)
                        break;
-
                buf = ((char *)buf) + cc;
                total += cc;
                len -= cc;
@@ -64,9 +62,7 @@ void xread(int fd, void *buf, size_t count)
 unsigned char xread_char(int fd)
 {
        char tmp;
-
        xread(fd, &tmp, 1);
-
        return tmp;
 }
 
@@ -88,20 +84,51 @@ char *reads(int fd, char *buffer, size_t size)
                *p++ = '\0';
                // avoid incorrect (unsigned) widening
                offset = (off_t)(p-buffer) - (off_t)size;
-               // set fd position the right after the \n
+               // set fd position right after '\n'
                if (offset && lseek(fd, offset, SEEK_CUR) == (off_t)-1)
                        return NULL;
        }
        return buffer;
 }
 
+// Read one line a-la fgets. Reads byte-by-byte.
+// Useful when it is important to not read ahead.
+char *xmalloc_reads(int fd, char *buf)
+{
+       char *p;
+       int sz = buf ? strlen(buf) : 0;
+
+       goto jump_in;
+       while (1) {
+               if (p - buf == sz) {
+ jump_in:
+                       buf = xrealloc(buf, sz + 128);
+                       p = buf + sz;
+                       sz += 128;
+               }
+               if (safe_read(fd, p, 1) != 1) { /* EOF/error */
+                       if (p == buf) {
+                               /* we read nothing [and buf was NULL initially] */
+                               free(buf);
+                               return NULL;
+                       }
+                       break;
+               }
+               if (*p == '\n')
+                       break;
+               p++;
+       }
+       *p++ = '\0';
+       return xrealloc(buf, p - buf);
+}
+
 ssize_t read_close(int fd, void *buf, size_t size)
 {
-       int e;
+       /*int e;*/
        size = full_read(fd, buf, size);
-       e = errno;
+       /*e = errno;*/
        close(fd);
-       errno = e;
+       /*errno = e;*/
        return size;
 }
 
@@ -113,25 +140,29 @@ ssize_t open_read_close(const char *filename, void *buf, size_t size)
        return read_close(fd, buf, size);
 }
 
+// Read (potentially big) files in one go. File size is estimated by
+// lseek to end.
 void *xmalloc_open_read_close(const char *filename, size_t *sizep)
 {
        char *buf;
        size_t size = sizep ? *sizep : INT_MAX;
-       int fd = xopen(filename, O_RDONLY);
+       int fd;
+       off_t len;
+
+       fd = xopen(filename, O_RDONLY);
        /* /proc/N/stat files report len 0 here */
        /* In order to make such files readable, we add small const */
-       off_t len = xlseek(fd, 0, SEEK_END) + 256;
+       len = xlseek(fd, 0, SEEK_END) | 0x3ff; /* + up to 1k */
        xlseek(fd, 0, SEEK_SET);
-
-       if (len > size)
-               bb_error_msg_and_die("file '%s' is too big", filename);
-       size = len;
+       if (len < size)
+               size = len;
        buf = xmalloc(size + 1);
        size = read_close(fd, buf, size);
        if ((ssize_t)size < 0)
-               bb_perror_msg_and_die("'%s'", filename);
+               bb_perror_msg_and_die("'%s'", filename);
        xrealloc(buf, size + 1);
        buf[size] = '\0';
-       if (sizep) *sizep = size;
+       if (sizep)
+               *sizep = size;
        return buf;
 }