177eed0b0b757749adcc17bcc92eb767536e458e
markd
  Fri Jan 10 10:13:42 2020 -0800
added mustSeek function

diff --git src/inc/common.h src/inc/common.h
index b891d98..ff03488 100644
--- src/inc/common.h
+++ src/inc/common.h
@@ -1143,30 +1143,33 @@
 
 #define writeOne(file, var) mustWrite((file), &(var), sizeof(var))
 /* Write out one variable to file. */
 
 void mustRead(FILE *file, void *buf, size_t size);
 /* Read size bytes from a file or squawk and die. */
 
 #define mustReadOne(file, var) mustRead((file), &(var), sizeof(var))
 /* Read one variable from file or die. */
 
 void mustGetLine(FILE *file, char *buf, int charCount);
 /* Read at most charCount-1 bytes from file, but stop after newline if one is
  * encountered.  The string in buf is '\0'-terminated.  (See man 3 fgets.)
  * Die if there is an error. */
 
+void mustSeek(FILE *file, off_t offset, int whence);
+/* Seek to given offset, relative to whence (see man fseek) in file or errAbort. */
+
 int mustOpenFd(char *fileName, int flags);
 /* Open a file descriptor (see man 2 open) or squawk and die. */
 
 void mustReadFd(int fd, void *buf, size_t size);
 /* Read size bytes from a file descriptor or squawk and die. */
 
 void mustWriteFd(int fd, void *buf, size_t size);
 /* Write size bytes to file descriptor fd or die.  (See man 2 write.) */
 
 off_t mustLseek(int fd, off_t offset, int whence);
 /* Seek to given offset, relative to whence (see man lseek) in file descriptor fd or errAbort.
  * Return final offset (e.g. if this is just an (fd, 0, SEEK_CUR) query for current position). */
 
 void mustCloseFd(int *pFd);
 /* Close file descriptor *pFd if >= 0, abort if there's an error, set *pFd = -1. */