fix problems found by Roman Sobkuliak

Author: Vladimir Kotal

files.tex

@@ -333,7 +333,7 @@
 
 \begin{itemize}
 \item what is ``normally'' visible in directory listings are hard links.
-W.r.t. files there are \emsl{only} hardlink a symlinks.
+W.r.t. files there are \emsl{only} hardlink and symlinks.
 
 \begin{description}
 \item[hardlink]~
@@ -445,7 +445,7 @@
 
 \begin{itemize}
 \item The \emph{FFS} file system introduced in 4.2BSD was historically the
-second unix file system. Some manufacturers of unix system started to prefer its
+second unix file system. Some manufacturers of unix system started to prefer it
 considering its better performance and new features, others remained with
 ifdef([[[NOSPELLCHECK]]], [[[\emph{s5fs}]]]) from compatibility reasons. This
 deepened the problem with already insufficient interoperability between
@@ -476,8 +476,8 @@
 depending on file system type (e.g. from the ifdef([[[NOSPELLCHECK]]],
 [[[\emph{ext2fs}]]]) module).
 Implementation dependent part of vnode structure is accessible only from
-functions of given file system; for kernel it is opaque. Next slide will shown
-another set of functions that works with file systems themselves.
+functions of given file system; for kernel it is opaque. See next slide
+for functions that operate on file system level.
 \emsl{This set defines VFS interface.}
 These \emsl{two sets together} constitute the vnode/VFS interface, generally
 referred to as VFS.
@@ -570,7 +570,7 @@
 \item If a filesystem is not correctly unmounted before the system is halted,
 the data can be inconsistent.
 \item The \texttt{fsck} command is used to check and correct file system.
-It tests progressively tests possible inconsistencies:
+It progressively tests possible inconsistencies:
     \begin{itemize}
     \setlength{\itemsep}{0ex}
     \item multiple references to the same block

history.tex

@@ -108,9 +108,9 @@
 \begin{itemize}
 \item ACM = Association for Computing Machinery, founded in 1947. UNIX was
 presented by Ken Thompson and Dennis Ritchie.
-\item \emsl{The act of rewriting UNIX to C was possible to most important moment
-in the history of this system} $\Rightarrow$ it was much easier to port UNIX to
-different architectures.
+\item \emsl{The act of rewriting UNIX to C was possibly the most important
+moment in the history of this system} $\Rightarrow$ it was much easier to port
+UNIX to different architectures.
 \item The legendary book \emph{A commentary on the Unix
 Operating System} by John Lions was found on version 6.
 \item Microsoft did not sell XENIX directly, it was licensed to OEM companies

intro.tex

@@ -1895,7 +1895,7 @@
 char *\emph{envp}[]);}
 ]]])
 \item The return value type of \texttt{main} should be always \texttt{int}.
-\emsl{Only lower 8 bits from that integer are only used though.}  It is always a
+\emsl{Only lower 8 bits from that integer are used though.}  It is always a
 non-negative number.  Note that in contrast to the C convention, the \texttt{0}
 return value means a success in a Unix shell, and a non-zero value means a
 failure.  A typical construct in a shell looks like this:

network.tex

@@ -1099,8 +1099,8 @@
 (\texttt{/etc/nsswitch.conf}) and the \texttt{flags} value.
 It performs the actions that would have to be otherwise done by
 \texttt{gethostbyaddr} and \texttt{getservbyport}.
-\item Either \texttt{host} or \texttt{port} can be \texttt{NULL} that
-means the caller is not interested in its resolution.
+\item Either \texttt{nodename} or \texttt{portname} can be \texttt{NULL} --
+that means the caller is not interested in its resolution.
 \item Unlike the above mentioned legacy functions \texttt{getnameinfo} is
 reentrant and is therefore safe to use with threads.
 \item The man page for \texttt{getnameinfo} contains the list of usable
@@ -1402,7 +1402,7 @@
 \texttt{FD\_SETSIZE}.
 \item Unlike \texttt{select} it is not necessary to refresh descriptor sets
 after each call or nullify \texttt{revents}. To deselect a file descriptor,
-set the \item \texttt{fd} member of the \texttt{pollfd} structure to -1
+set the \texttt{fd} member of the \texttt{pollfd} structure to -1
 (or reshuffle the array which is significantly more complex).
 \item Time set to -1 has the same effect as \texttt{NULL} for \texttt{select}.
 \item If the number of descriptors is set to 0 (\texttt{fds} should be then

other.tex

@@ -22,9 +22,8 @@
 read-only memory will result in the \texttt{SIGSEGV} signal to be delivered.
 \item[swap:] swap area is created on separate disk partition, since
 SVR4 it can be also in a file.
-\item[swapper:] the \texttt{swapper} process tries to saved a process that is
-not into memory to disk and use the free space for process that was swapped out
-earlier.
+\item[swapper:] the \texttt{swapper} process tries to save a process
+to disk and use the free space for a process that was swapped out earlier.
 \item[demand paging:] when a process requests a memory only the page is
 modified. The first instruction addressing the page contents will result in an
 exception. The kernel will handle it by allocating a page.

proc.tex

@@ -448,10 +448,10 @@
 \item returns the PGID of the calling process
 \end{itemize}
 ifdef([[[NOSPELLCHECK]]], [[[
-\texttt{pid\_t \funnm{getppid}(void);} 
+\texttt{pid\_t \funnm{getppid}(void);}
 ]]])
 \begin{itemize}
-\item returns the process ID of the calling process.
+\item returns the process ID of the parent process.
 \end{itemize}
 ifdef([[[NOSPELLCHECK]]], [[[
 \texttt{pid\_t \funnm{getsid}(pid\_t \emph{pid});}
@@ -466,7 +466,8 @@
 \item[process groups] make it possible to send signals to group of processes
 at once
 \item[session] is a collection of processes created for (\emph{job control}).
-The processes of the session shared one \emph{controlling terminal}.
+
+The processes of the session share one \emph{controlling terminal}.
 Session includes one or more process groups. Maximum one group in the session
 runs in foreground (\emph{foreground process group}) and has access to the
 controlling terminal for input and output, the rest is running in the background
@@ -998,7 +999,7 @@
 calls
 \begin{itemize}
 \item pros: processes cannot corrupt address space of one another
-\item const: significant syscall overhead (typically \funnm{read},
+\item cons: significant syscall overhead (typically \funnm{read},
 \funnm{write})
 \end{itemize}
 \item \emph{shared memory} means to map a part of memory into an address space
@@ -1152,7 +1153,7 @@
     \item \texttt{MS\_ASYNC} \dots{} asynchronous write
     \item \texttt{MS\_SYNC} \dots{} synchronous write
     \item \texttt{MS\_INVALIDATE} \dots{} destroy mapped data,
-    that are differ from file contents
+    different to file contents
     \end{itemize}
 \end{itemize}
 ifdef([[[NOSPELLCHECK]]], [[[
@@ -1284,10 +1285,11 @@
     \item \texttt{RTLD\_GLOBAL} \dots{} symbols defined by the shared object
     will be  made available for symbol resolution of subsequently loaded
     objects.  That is the default for objects mapped when executing a program.
-    For \funnm{dlopen}, the default is \texttt{RTLD\_LOCAL}.  It means you can
-    map the same library multiple time via \funnm{dlopen} and the symbols in the
-    mapped instances of the same library will not overlap.  However, all
-    globally mapped symbols from there are shared, e.g. \texttt{errno}.
+    For \funnm{dlopen}, the default is \texttt{RTLD\_LOCAL}.  It means
+    the same library can be mapped multiple times via \funnm{dlopen} and the
+    symbols in the mapped instances of the same library will not overlap.
+    However, all globally mapped symbols from there are shared, e.g.
+    \texttt{errno}.
     \end{itemize}
 \item \label{RTLD_NEXT} Special handle \texttt{RTLD\_NEXT} searches the symbol
 only in libraries loaded after the library that called \funnm{dlsym}.  Handy for

synchro.tex

@@ -191,10 +191,10 @@
 to be unlocked.
 \item reader process locks the file for reading. Writers have to wait
 for the lock, other readers can also lock the file for reading and read data.
-\item in each moment there can be at most active lock for writing or multiple
-locks for reading. Both locks cannot be locked simultaneously.
+\item in each moment there can be at most one active lock for writing or
+multiple locks for reading. Both locks cannot be locked simultaneously.
 \item for efficiency each process should hold the lock for shortest time
-possible and if possible do not lock the whole file -- only the section that 
+possible and if possible do not lock the whole file -- only the section that
 is being worked with. Passive waiting is preferred, active waiting is
 suitable for very short time.
 \end{itemize}

threads.tex

@@ -878,8 +878,8 @@
 \texttt{int \funnm{pthread\_mutex\_unlock}(pthread\_mutex\_t *\emph{mx});}
 ]]])
 \begin{itemize}
-\item If a mutex is already locked, the attempt to acquire it will result on the
-thread being locked (depending on mutex type).
+\item If a mutex is already locked, the attempt to acquire it will result
+in the thread being locked (depending on mutex type).
 It is possible to use:
 \end{itemize}
 ifdef([[[NOSPELLCHECK]]], [[[