review, mark env variables, linkify

1 files changed, 180 insertions, 179 deletions

diff --git a/docs/env_variables.md b/docs/env_variables.md
index 49eadcaa..a36f2b4e 100644
--- a/docs/env_variables.md
+++ b/docs/env_variables.md
@@ -2,63 +2,64 @@
 
   This document discusses the environment variables used by American Fuzzy Lop++
   to expose various exotic functions that may be (rarely) useful for power
-  users or for some types of custom fuzzing setups. See README.md for the general
+  users or for some types of custom fuzzing setups. See [README.md](README.md) for the general
   instruction manual.
 
 ## 1) Settings for all compilers
 
 Starting with afl++ 3.0 there is only one compiler: afl-cc
 To select the different instrumentation modes this can be done by
-  1. passing --afl-MODE command line options to the compiler
-  2. use a symlink to afl-cc: afl-gcc, afl-g++, afl-clang, afl-clang++,
+  1. passing the --afl-MODE command line option to the compiler
+  2. or using a symlink to afl-cc: afl-gcc, afl-g++, afl-clang, afl-clang++,
      afl-clang-fast, afl-clang-fast++, afl-clang-lto, afl-clang-lto++,
      afl-gcc-fast, afl-g++-fast
-  3. using the environment variable AFL_CC_COMPILER with MODE
+  3. or using the environment variable `AFL_CC_COMPILER` with `MODE`
 
-MODE can one of LTO (afl-clang-lto*), LLVM (afl-clang-fast*), GCC_PLUGIN
-(afl-g*-fast) or GCC (afl-gcc/afl-g++).
+`MODE` can be one of `LTO` (afl-clang-lto*), `LLVM` (afl-clang-fast*), `GCC_PLUGIN`
+(afl-g*-fast) or `GCC` (afl-gcc/afl-g++).
 
-Because beside the --afl-MODE command no afl specific command-line options
-are accepted, the compile-time tools make fairly broad use of environmental
-variables:
 
-  - Most afl tools do not print any ouput if stout/stderr are redirected.
-    If you want to have the output into a file then set the AFL_DEBUG
+Because (with the exception of the --afl-MODE command line option) the
+compile-time tools do not accept afl specific command-line options, they
+make fairly broad use of environmental variables instead:
+
+  - Most afl tools do not print any output if stdout/stderr are redirected.
+    If you want to get the output into a file then set the `AFL_DEBUG`
     environment variable.
     This is sadly necessary for various build processes which fail otherwise.
 
-  - Setting AFL_HARDEN automatically adds code hardening options when invoking
-    the downstream compiler. This currently includes -D_FORTIFY_SOURCE=2 and
-    -fstack-protector-all. The setting is useful for catching non-crashing
+  - Setting `AFL_HARDEN` automatically adds code hardening options when invoking
+    the downstream compiler. This currently includes `-D_FORTIFY_SOURCE=2` and
+    `-fstack-protector-all`. The setting is useful for catching non-crashing
     memory bugs at the expense of a very slight (sub-5%) performance loss.
 
-  - By default, the wrapper appends -O3 to optimize builds. Very rarely, this
-    will cause problems in programs built with -Werror, simply because -O3
+  - By default, the wrapper appends `-O3` to optimize builds. Very rarely, this
+    will cause problems in programs built with -Werror, simply because `-O3`
     enables more thorough code analysis and can spew out additional warnings.
-    To disable optimizations, set AFL_DONT_OPTIMIZE.
-    However if -O... and/or -fno-unroll-loops are set, these are not
-    overriden.
+    To disable optimizations, set `AFL_DONT_OPTIMIZE`.
+    However if `-O...` and/or `-fno-unroll-loops` are set, these are not
+    overridden.
 
-  - Setting AFL_USE_ASAN automatically enables ASAN, provided that your
+  - Setting `AFL_USE_ASAN` automatically enables ASAN, provided that your
     compiler supports that. Note that fuzzing with ASAN is mildly challenging
     - see [notes_for_asan.md](notes_for_asan.md).
 
-    (You can also enable MSAN via AFL_USE_MSAN; ASAN and MSAN come with the
+    (You can also enable MSAN via `AFL_USE_MSAN`; ASAN and MSAN come with the
     same gotchas; the modes are mutually exclusive. UBSAN can be enabled
-    similarly by setting the environment variable AFL_USE_UBSAN=1. Finally
+    similarly by setting the environment variable `AFL_USE_UBSAN=1`. Finally
     there is the Control Flow Integrity sanitizer that can be activated by
-    AFL_USE_CFISAN=1)
+    `AFL_USE_CFISAN=1`)
 
-  - Setting AFL_CC, AFL_CXX, and AFL_AS lets you use alternate downstream
+  - Setting `AFL_CC`, `AFL_CXX`, and `AFL_AS` lets you use alternate downstream
     compilation tools, rather than the default 'clang', 'gcc', or 'as' binaries
-    in your $PATH.
+    in your `$PATH`.
 
-  - AFL_PATH can be used to point afl-gcc to an alternate location of afl-as.
+  - `AFL_PATH` can be used to point afl-gcc to an alternate location of afl-as.
     One possible use of this is examples/clang_asm_normalize/, which lets
     you instrument hand-written assembly when compiling clang code by plugging
     a normalizer into the chain. (There is no equivalent feature for GCC.)
 
-  - Setting AFL_INST_RATIO to a percentage between 0 and 100% controls the
+  - Setting `AFL_INST_RATIO` to a percentage between 0 and 100 controls the
     probability of instrumenting every branch. This is (very rarely) useful
     when dealing with exceptionally complex programs that saturate the output
     bitmap. Examples include v8, ffmpeg, and perl.
@@ -66,51 +67,51 @@ variables:
     (If this ever happens, afl-fuzz will warn you ahead of the time by
     displaying the "bitmap density" field in fiery red.)
 
-    Setting AFL_INST_RATIO to 0 is a valid choice. This will instrument only
+    Setting `AFL_INST_RATIO` to 0 is a valid choice. This will instrument only
     the transitions between function entry points, but not individual branches.
 
     Note that this is an outdated variable. A few instances (e.g. afl-gcc)
     still support these, but state-of-the-art (e.g. LLVM LTO and LLVM PCGUARD)
     do not need this.
 
-  - AFL_NO_BUILTIN causes the compiler to generate code suitable for use with
+  - `AFL_NO_BUILTIN` causes the compiler to generate code suitable for use with
     libtokencap.so (but perhaps running a bit slower than without the flag).
 
-  - TMPDIR is used by afl-as for temporary files; if this variable is not set,
+  - `TMPDIR` is used by afl-as for temporary files; if this variable is not set,
     the tool defaults to /tmp.
 
   - If you are a weird person that wants to compile and instrument asm
-    text files then use the AFL_AS_FORCE_INSTRUMENT variable:
-      AFL_AS_FORCE_INSTRUMENT=1 afl-gcc foo.s -o foo
+    text files then use the `AFL_AS_FORCE_INSTRUMENT` variable:
+      `AFL_AS_FORCE_INSTRUMENT=1 afl-gcc foo.s -o foo`
 
-  - Setting AFL_QUIET will prevent afl-cc and afl-as banners from being
+  - Setting `AFL_QUIET` will prevent afl-cc and afl-as banners from being
     displayed during compilation, in case you find them distracting.
 
-  - Setting AFL_CAL_FAST will speed up the initial calibration, if the
-    application is very slow
+  - Setting `AFL_CAL_FAST` will speed up the initial calibration, if the
+    application is very slow.
 
 ## 2) Settings for LLVM and LTO: afl-clang-fast / afl-clang-fast++ / afl-clang-lto / afl-clang-lto++
 
 The native instrumentation helpers (instrumentation and gcc_plugin) accept a subset
-of the settings discussed in section #1, with the exception of:
+of the settings discussed in section 1, with the exception of:
 
   - LLVM modes support `AFL_LLVM_DICT2FILE=/absolute/path/file.txt` which will
-    write all constant string comparisons  to this file to be used with
+    write all constant string comparisons  to this file to be used later with
     afl-fuzz' `-x` option.
 
-  - AFL_AS, since this toolchain does not directly invoke GNU as.
+  - `AFL_AS`, since this toolchain does not directly invoke GNU as.
 
-  - TMPDIR and AFL_KEEP_ASSEMBLY, since no temporary assembly files are
+  - `TMPDIR` and `AFL_KEEP_ASSEMBLY`, since no temporary assembly files are
     created.
 
-  - AFL_INST_RATIO, as we by default collision free instrumentation is used.
+  - `AFL_INST_RATIO`, as we by default use collision free instrumentation.
     Not all passes support this option though as it is an outdated feature.
 
-Then there are a few specific features that are only available in instrumentation:
+Then there are a few specific features that are only available in instrumentation mode:
 
 ### Select the instrumentation mode
 
-    - AFL_LLVM_INSTRUMENT - this configures the instrumentation mode. 
+    - `AFL_LLVM_INSTRUMENT` - this configures the instrumentation mode. 
       Available options:
         CLASSIC - classic AFL (map[cur_loc ^ prev_loc >> 1]++) (default)
         CFG - InsTrim instrumentation (see below)
@@ -119,148 +120,148 @@ Then there are a few specific features that are only available in instrumentatio
         NGRAM-x - deeper previous location coverage (from NGRAM-2 up to NGRAM-16)
       In CLASSIC (default) and CFG/INSTRIM you can also specify CTX and/or
       NGRAM, seperate the options with a comma "," then, e.g.:
-        AFL_LLVM_INSTRUMENT=CFG,CTX,NGRAM-4
+        `AFL_LLVM_INSTRUMENT=CFG,CTX,NGRAM-4`
       Not that this is a good idea to use both CTX and NGRAM :)
 
 ### LTO
 
-    This is a different kind way of instrumentation: first it compiles all
+  This is a different kind way of instrumentation: first it compiles all
     code in LTO (link time optimization) and then performs an edge inserting
     instrumentation which is 100% collision free (collisions are a big issue
     in afl and afl-like instrumentations). This is performed by using
     afl-clang-lto/afl-clang-lto++ instead of afl-clang-fast, but is only
     built if LLVM 11 or newer is used.
 
-   - AFL_LLVM_INSTRUMENT=CFG will use Control Flow Graph instrumentation.
+   - `AFL_LLVM_INSTRUMENT=CFG` will use Control Flow Graph instrumentation.
      (not recommended for afl-clang-fast, default for afl-clang-lto as there
       it is a different and better kind of instrumentation.)
 
-    None of the following options are necessary to be used and are rather for
+  None of the following options are necessary to be used and are rather for
     manual use (which only ever the author of this LTO implementation will use).
-    These are used if several seperated instrumentation are performed which
+    These are used if several separated instrumentations are performed which
     are then later combined.
 
-   - AFL_LLVM_DOCUMENT_IDS=file will document to a file which edge ID was given
+   - `AFL_LLVM_DOCUMENT_IDS=file` will document to a file which edge ID was given
      to which function. This helps to identify functions with variable bytes
      or which functions were touched by an input.
-   - AFL_LLVM_MAP_ADDR sets the fixed map address to a different address than
-     the default 0x10000. A value of 0 or empty sets the map address to be
+   - `AFL_LLVM_MAP_ADDR` sets the fixed map address to a different address than
+     the default `0x10000`. A value of 0 or empty sets the map address to be
      dynamic (the original afl way, which is slower)
-   - AFL_LLVM_MAP_DYNAMIC sets the shared memory address to be dynamic
-   - AFL_LLVM_LTO_STARTID sets the starting location ID for the instrumentation.
+   - `AFL_LLVM_MAP_DYNAMIC` sets the shared memory address to be dynamic
+   - `AFL_LLVM_LTO_STARTID` sets the starting location ID for the instrumentation.
      This defaults to 1
-   - AFL_LLVM_LTO_DONTWRITEID prevents that the highest location ID written
+   - `AFL_LLVM_LTO_DONTWRITEID` prevents that the highest location ID written
      into the instrumentation is set in a global variable
 
-    See instrumentation/README.LTO.md for more information.
+  See [instrumentation/README.lto.md](../instrumentation/README.lto.md) for more information.
 
 ### INSTRIM
 
-    This feature increases the speed by ~15% without any disadvantages to the
+  This feature increases the speed by ~15% without any disadvantages to the
     classic instrumentation.
 
-    Note that there is also an LTO version (if you have llvm 11 or higher) -
+  Note that there is also an LTO version (if you have llvm 11 or higher) -
     that is the best instrumentation we have. Use `afl-clang-lto` to activate.
     The InsTrim LTO version additionally has all the options and features of
     LTO (see above).
 
-    - Setting AFL_LLVM_INSTRIM or AFL_LLVM_INSTRUMENT=CFG to activates this mode
+   - Setting `AFL_LLVM_INSTRIM` or `AFL_LLVM_INSTRUMENT=CFG` activates this mode
 
-    - Setting AFL_LLVM_INSTRIM_LOOPHEAD=1 expands on INSTRIM to optimize loops.
+   - Setting `AFL_LLVM_INSTRIM_LOOPHEAD=1` expands on INSTRIM to optimize loops.
       afl-fuzz will only be able to see the path the loop took, but not how
       many times it was called (unless it is a complex loop).
 
-    See instrumentation/README.instrim.md
+  See [instrumentation/README.instrim.md](../instrumentation/README.instrim.md)
 
 ### NGRAM
 
-    - Setting AFL_LLVM_NGRAM_SIZE or AFL_LLVM_INSTRUMENT=NGRAM-{value}
+   - Setting `AFL_LLVM_NGRAM_SIZE` or `AFL_LLVM_INSTRUMENT=NGRAM-{value}`
       activates ngram prev_loc coverage, good values are 2, 4 or 8
       (any value between 2 and 16 is valid).
-      It is highly recommended to increase the MAP_SIZE_POW2 definition in
+      It is highly recommended to increase the `MAP_SIZE_POW2` definition in
       config.h to at least 18 and maybe up to 20 for this as otherwise too
       many map collisions occur.
 
-    See instrumentation/README.ctx.md
+  See [instrumentation/README.ngram.md](../instrumentation/README.ngram.md)
 
 ### CTX
 
-    - Setting AFL_LLVM_CTX or AFL_LLVM_INSTRUMENT=CTX
+   - Setting `AFL_LLVM_CTX` or `AFL_LLVM_INSTRUMENT=CTX`
       activates context sensitive branch coverage - meaning that each edge
       is additionally combined with its caller.
-      It is highly recommended to increase the MAP_SIZE_POW2 definition in
+      It is highly recommended to increase the `MAP_SIZE_POW2` definition in
       config.h to at least 18 and maybe up to 20 for this as otherwise too
       many map collisions occur.
 
-    See instrumentation/README.ngram.md
+  See [instrumentation/README.ctx.md](../instrumentation/README.ctx.md)
 
 ### LAF-INTEL
 
-    This great feature will split compares to series of single byte comparisons
+  This great feature will split compares into series of single byte comparisons
     to allow afl-fuzz to find otherwise rather impossible paths. It is not
     restricted to Intel CPUs ;-)
 
-    - Setting AFL_LLVM_LAF_TRANSFORM_COMPARES will split string compare functions
+   - Setting `AFL_LLVM_LAF_TRANSFORM_COMPARES` will split string compare functions
 
-    - Setting AFL_LLVM_LAF_SPLIT_SWITCHES will split switch()es
+   - Setting `AFL_LLVM_LAF_SPLIT_SWITCHES` will split all `switch` constructs
 
-    - Setting AFL_LLVM_LAF_SPLIT_COMPARES will split all floating point and
+   - Setting `AFL_LLVM_LAF_SPLIT_COMPARES` will split all floating point and
       64, 32 and 16 bit integer CMP instructions
 
-    - Setting AFL_LLVM_LAF_SPLIT_FLOATS will split floating points, needs
+   - Setting `AFL_LLVM_LAF_SPLIT_FLOATS` will split floating points, needs
       AFL_LLVM_LAF_SPLIT_COMPARES to be set
 
-    - Setting AFL_LLVM_LAF_ALL sets all of the above
+   - Setting `AFL_LLVM_LAF_ALL` sets all of the above
 
-    See instrumentation/README.laf-intel.md for more information.
+  See [instrumentation/README.laf-intel.md](../instrumentation/README.laf-intel.md) for more information.
 
 ### INSTRUMENT LIST (selectively instrument files and functions)
 
-    This feature allows selectively instrumentation of the source
+  This feature allows selective instrumentation of the source
 
-    - Setting AFL_LLVM_ALLOWLIST or AFL_LLVM_DENYLIST with a filenames and/or
+   - Setting `AFL_LLVM_ALLOWLIST` or `AFL_LLVM_DENYLIST` with a filenames and/or
       function will only instrument (or skip) those files that match the names
       listed in the specified file.
 
-    See instrumentation/README.instrument_list.md for more information.
+  See [instrumentation/README.instrument_list.md](../instrumentation/README.instrument_list.md) for more information.
 
 ### NOT_ZERO
 
-    - Setting AFL_LLVM_NOT_ZERO=1 during compilation will use counters
+   - Setting `AFL_LLVM_NOT_ZERO=1` during compilation will use counters
       that skip zero on overflow. This is the default for llvm >= 9,
       however for llvm versions below that this will increase an unnecessary
       slowdown due a performance issue that is only fixed in llvm 9+.
       This feature increases path discovery by a little bit.
 
-    - Setting AFL_LLVM_SKIP_NEVERZERO=1 will not implement the skip zero
+   - Setting `AFL_LLVM_SKIP_NEVERZERO=1` will not implement the skip zero
       test. If the target performs only few loops then this will give a
       small performance boost.
 
-    See instrumentation/README.neverzero.md
+  See [instrumentation/README.neverzero.md](../instrumentation/README.neverzero.md)
 
 ### CMPLOG
 
-    - Setting AFL_LLVM_CMPLOG=1 during compilation will tell afl-clang-fast to
-      produce a CmpLog binary. See instrumentation/README.cmplog.md
+   - Setting `AFL_LLVM_CMPLOG=1` during compilation will tell afl-clang-fast to
+      produce a CmpLog binary.
 
-    See instrumentation/README.neverzero.md
+  See [instrumentation/README.cmplog.md](../instrumentation/README.cmplog.md)
 
 ## 3) Settings for GCC / GCC_PLUGIN modes
 
 Then there are a few specific features that are only available in GCC and
 GCC_PLUGIN mode.
 
-  - Setting AFL_KEEP_ASSEMBLY prevents afl-as from deleting instrumented
+  - Setting `AFL_KEEP_ASSEMBLY` prevents afl-as from deleting instrumented
     assembly files. Useful for troubleshooting problems or understanding how
     the tool works. (GCC mode only)
     To get them in a predictable place, try something like:
-
+```
     mkdir assembly_here
     TMPDIR=$PWD/assembly_here AFL_KEEP_ASSEMBLY=1 make clean all
-
-  - Setting AFL_GCC_INSTRUMENT_FILE with a filename will only instrument those
+```
+  - Setting `AFL_GCC_INSTRUMENT_FILE` with a filename will only instrument those
     files that match the names listed in this file (one filename per line).
-    See gcc_plugin/README.instrument_list.md for more information.
+    See [instrumentation/README.instrument_list.md](../instrumentation/README.instrument_list.md) for more information.
     (GCC_PLUGIN mode only)
 
 ## 4) Settings for afl-fuzz
@@ -268,127 +269,127 @@ GCC_PLUGIN mode.
 The main fuzzer binary accepts several options that disable a couple of sanity
 checks or alter some of the more exotic semantics of the tool:
 
-  - Setting AFL_SKIP_CPUFREQ skips the check for CPU scaling policy. This is
+  - Setting `AFL_SKIP_CPUFREQ` skips the check for CPU scaling policy. This is
     useful if you can't change the defaults (e.g., no root access to the
     system) and are OK with some performance loss.
 
-  - AFL_EXIT_WHEN_DONE causes afl-fuzz to terminate when all existing paths
+  - `AFL_EXIT_WHEN_DONE` causes afl-fuzz to terminate when all existing paths
     have been fuzzed and there were no new finds for a while. This would be
     normally indicated by the cycle counter in the UI turning green. May be
     convenient for some types of automated jobs.
 
-  - AFL_MAP_SIZE sets the size of the shared map that afl-fuzz, afl-showmap,
+  - `AFL_MAP_SIZE` sets the size of the shared map that afl-fuzz, afl-showmap,
     afl-tmin and afl-analyze create to gather instrumentation data from
     the target. This must be equal or larger than the size the target was
     compiled with.
 
-  - AFL_TESTCACHE_SIZE allows you to overrider the define in config.h for
-    TESTCASE_CACHE. Recommended values are 50-250MB - or more if your
-    fuzzing finds a huge amount of paths for large inputs.
+  - `AFL_TESTCACHE_SIZE` allows you to override the size of `#define TESTCASE_CACHE`
+    in config.h. Recommended values are 50-250MB - or more if your fuzzing
+    finds a huge amount of paths for large inputs.
 
-  - Setting AFL_DISABLE_TRIM tells afl-fuzz to no trim test cases. This is
+  - Setting `AFL_DISABLE_TRIM` tells afl-fuzz not to trim test cases. This is
     usually a bad idea!
 
-  - Setting AFL_NO_AFFINITY disables attempts to bind to a specific CPU core
+  - Setting `AFL_NO_AFFINITY` disables attempts to bind to a specific CPU core
     on Linux systems. This slows things down, but lets you run more instances
     of afl-fuzz than would be prudent (if you really want to).
 
-  - AFL_SKIP_CRASHES causes AFL to tolerate crashing files in the input
+  - `AFL_SKIP_CRASHES` causes AFL++ to tolerate crashing files in the input
     queue. This can help with rare situations where a program crashes only
     intermittently, but it's not really recommended under normal operating
     conditions.
 
-  - Setting AFL_HANG_TMOUT allows you to specify a different timeout for
+  - Setting `AFL_HANG_TMOUT` allows you to specify a different timeout for
     deciding if a particular test case is a "hang". The default is 1 second
-    or the value of the -t parameter, whichever is larger. Dialing the value
+    or the value of the `-t` parameter, whichever is larger. Dialing the value
     down can be useful if you are very concerned about slow inputs, or if you
-    don't want AFL to spend too much time classifying that stuff and just
+    don't want AFL++ to spend too much time classifying that stuff and just
     rapidly put all timeouts in that bin.
 
-  - AFL_NO_ARITH causes AFL to skip most of the deterministic arithmetics.
+  - `AFL_NO_ARITH` causes AFL++ to skip most of the deterministic arithmetics.
     This can be useful to speed up the fuzzing of text-based file formats.
 
-  - AFL_NO_SNAPSHOT will advice afl-fuzz not to use the snapshot feature
+  - `AFL_NO_SNAPSHOT` will advice afl-fuzz not to use the snapshot feature
     if the snapshot lkm is loaded
 
-  - AFL_SHUFFLE_QUEUE randomly reorders the input queue on startup. Requested
+  - `AFL_SHUFFLE_QUEUE` randomly reorders the input queue on startup. Requested
     by some users for unorthodox parallelized fuzzing setups, but not
     advisable otherwise.
 
-  - AFL_TMPDIR is used to write the .cur_input file to if exists, and in
+  - `AFL_TMPDIR` is used to write the `.cur_input` file to if exists, and in
     the normal output directory otherwise. You would use this to point to
     a ramdisk/tmpfs. This increases the speed by a small value but also
     reduces the stress on SSDs.
 
   - When developing custom instrumentation on top of afl-fuzz, you can use
-    AFL_SKIP_BIN_CHECK to inhibit the checks for non-instrumented binaries
-    and shell scripts; and AFL_DUMB_FORKSRV in conjunction with the -n
+    `AFL_SKIP_BIN_CHECK` to inhibit the checks for non-instrumented binaries
+    and shell scripts; and `AFL_DUMB_FORKSRV` in conjunction with the `-n`
     setting to instruct afl-fuzz to still follow the fork server protocol
     without expecting any instrumentation data in return.
 
-  - When running in the -M or -S mode, setting AFL_IMPORT_FIRST causes the
+  - When running in the `-M` or `-S` mode, setting `AFL_IMPORT_FIRST` causes the
     fuzzer to import test cases from other instances before doing anything
     else. This makes the "own finds" counter in the UI more accurate.
     Beyond counter aesthetics, not much else should change.
 
-  - Note that AFL_POST_LIBRARY is deprecated, use AFL_CUSTOM_MUTATOR_LIBRARY
+  - Note that `AFL_POST_LIBRARY` is deprecated, use `AFL_CUSTOM_MUTATOR_LIBRARY`
     instead (see below).
 
-  - Setting AFL_CUSTOM_MUTATOR_LIBRARY to a shared library with
+  - Setting `AFL_CUSTOM_MUTATOR_LIBRARY` to a shared library with
     afl_custom_fuzz() creates additional mutations through this library.
     If afl-fuzz is compiled with Python (which is autodetected during builing
-    afl-fuzz), setting AFL_PYTHON_MODULE to a Python module can also provide
+    afl-fuzz), setting `AFL_PYTHON_MODULE` to a Python module can also provide
     additional mutations.
-    If AFL_CUSTOM_MUTATOR_ONLY is also set, all mutations will solely be
+    If `AFL_CUSTOM_MUTATOR_ONLY` is also set, all mutations will solely be
     performed with the custom mutator.
     This feature allows to configure custom mutators which can be very helpful,
     e.g. fuzzing XML or other highly flexible structured input.
     Please see [custom_mutators.md](custom_mutators.md).
 
-  - AFL_FAST_CAL keeps the calibration stage about 2.5x faster (albeit less
+  - `AFL_FAST_CAL` keeps the calibration stage about 2.5x faster (albeit less
     precise), which can help when starting a session against a slow target.
 
   - The CPU widget shown at the bottom of the screen is fairly simplistic and
     may complain of high load prematurely, especially on systems with low core
-    counts. To avoid the alarming red color, you can set AFL_NO_CPU_RED.
+    counts. To avoid the alarming red color, you can set `AFL_NO_CPU_RED`.
 
-  - In QEMU mode (-Q), AFL_PATH will be searched for afl-qemu-trace.
+  - In QEMU mode (-Q), `AFL_PATH` will be searched for afl-qemu-trace.
 
-  - Setting AFL_CYCLE_SCHEDULES will switch to a different schedule everytime
+  - Setting `AFL_CYCLE_SCHEDULES` will switch to a different schedule everytime
     a cycle is finished.
 
-  - Setting AFL_EXPAND_HAVOC_NOW will start in the extended havoc mode that
+  - Setting `AFL_EXPAND_HAVOC_NOW` will start in the extended havoc mode that
     includes costly mutations. afl-fuzz automatically enables this mode when
     deemed useful otherwise.
 
-  - Setting AFL_PRELOAD causes AFL to set LD_PRELOAD for the target binary
+  - Setting `AFL_PRELOAD` causes AFL++ to set `LD_PRELOAD` for the target binary
     without disrupting the afl-fuzz process itself. This is useful, among other
     things, for bootstrapping libdislocator.so.
 
-  - Setting AFL_NO_UI inhibits the UI altogether, and just periodically prints
+  - Setting `AFL_NO_UI` inhibits the UI altogether, and just periodically prints
     some basic stats. This behavior is also automatically triggered when the
     output from afl-fuzz is redirected to a file or to a pipe.
 
-  - Setting AFL_FORCE_UI will force painting the UI on the screen even if
+  - Setting `AFL_FORCE_UI` will force painting the UI on the screen even if
     no valid terminal was detected (for virtual consoles)
 
-  - If you are Jakub, you may need AFL_I_DONT_CARE_ABOUT_MISSING_CRASHES.
+  - If you are Jakub, you may need `AFL_I_DONT_CARE_ABOUT_MISSING_CRASHES`.
     Others need not apply.
 
-  - Benchmarking only: AFL_BENCH_JUST_ONE causes the fuzzer to exit after
-    processing the first queue entry; and AFL_BENCH_UNTIL_CRASH causes it to
+  - Benchmarking only: `AFL_BENCH_JUST_ONE` causes the fuzzer to exit after
+    processing the first queue entry; and `AFL_BENCH_UNTIL_CRASH` causes it to
     exit soon after the first crash is found.
 
-  - Setting AFL_DEBUG_CHILD_OUTPUT will not suppress the child output.
+  - Setting `AFL_DEBUG_CHILD_OUTPUT` will not suppress the child output.
     Not pretty but good for debugging purposes.
 
-  - Setting AFL_NO_CPU_RED will not display very high cpu usages in red color.
+  - Setting `AFL_NO_CPU_RED` will not display very high cpu usages in red color.
 
-  - Setting AFL_AUTORESUME will resume a fuzz run (same as providing `-i -`)
+  - Setting `AFL_AUTORESUME` will resume a fuzz run (same as providing `-i -`)
     for an existing out folder, even if a different `-i` was provided.
     Without this setting, afl-fuzz will refuse execution for a long-fuzzed out dir.
 
-  - Setting AFL_NO_FORKSRV disables the forkserver optimization, reverting to
+  - Setting `AFL_NO_FORKSRV` disables the forkserver optimization, reverting to
     fork + execve() call for every tested input. This is useful mostly when
     working with unruly libraries that create threads or do other crazy
     things when initializing (before the instrumentation has a chance to run).
@@ -397,128 +398,128 @@ checks or alter some of the more exotic semantics of the tool:
     normally done when starting up the forkserver and causes a pretty
     significant performance drop.
 
-  - Setting AFL_STATSD enable StatsD metrics collection.
-    By default AFL will send these metrics over UDP to 127.0.0.1:8125.
-    The host and port are configurable with AFL_STATSD_HOST and AFL_STATSD_PORT
+  - Setting `AFL_STATSD` enable StatsD metrics collection.
+    By default AFL++ will send these metrics over UDP to 127.0.0.1:8125.
+    The host and port are configurable with `AFL_STATSD_HOST` and `AFL_STATSD_PORT`
     respectively.
-    To get the most out of this, you should provide AFL_STATSD_TAGS_FLAVOR that
+    To get the most out of this, you should provide `AFL_STATSD_TAGS_FLAVOR` that
     matches your StatsD server.
     Available flavors are `dogstatsd`, `librato`, `signalfx` and `influxdb`.
 
-  - Outdated environment variables that are that not supported anymore:
-    AFL_DEFER_FORKSRV
-    AFL_PERSISTENT
+  - Outdated environment variables that are not supported anymore:
+    `AFL_DEFER_FORKSRV`
+    `AFL_PERSISTENT`
 
 ## 5) Settings for afl-qemu-trace
 
 The QEMU wrapper used to instrument binary-only code supports several settings:
 
-  - It is possible to set AFL_INST_RATIO to skip the instrumentation on some
+  - It is possible to set `AFL_INST_RATIO` to skip the instrumentation on some
     of the basic blocks, which can be useful when dealing with very complex
     binaries.
 
-  - Setting AFL_INST_LIBS causes the translator to also instrument the code
+  - Setting `AFL_INST_LIBS` causes the translator to also instrument the code
     inside any dynamically linked libraries (notably including glibc).
 
-  - Setting AFL_COMPCOV_LEVEL enables the CompareCoverage tracing of all cmp
+  - Setting `AFL_COMPCOV_LEVEL` enables the CompareCoverage tracing of all cmp
     and sub in x86 and x86_64 and memory comparions functions (e.g. strcmp,
-    memcmp, ...) when libcompcov is preloaded using AFL_PRELOAD.
+    memcmp, ...) when libcompcov is preloaded using `AFL_PRELOAD`.
     More info at qemu_mode/libcompcov/README.md.
-    There are two levels at the moment, AFL_COMPCOV_LEVEL=1 that instruments
+    There are two levels at the moment, `AFL_COMPCOV_LEVEL=1` that instruments
     only comparisons with immediate values / read-only memory and
-    AFL_COMPCOV_LEVEL=2 that instruments all the comparions. Level 2 is more
+    `AFL_COMPCOV_LEVEL=2` that instruments all the comparions. Level 2 is more
     accurate but may need a larger shared memory.
 
-  - Setting AFL_QEMU_COMPCOV enables the CompareCoverage tracing of all
+  - Setting `AFL_QEMU_COMPCOV` enables the CompareCoverage tracing of all
     cmp and sub in x86 and x86_64.
-    This is an alias of AFL_COMPCOV_LEVEL=1 when AFL_COMPCOV_LEVEL is
+    This is an alias of `AFL_COMPCOV_LEVEL=1` when `AFL_COMPCOV_LEVEL` is
     not specified.
 
   - The underlying QEMU binary will recognize any standard "user space
-    emulation" variables (e.g., QEMU_STACK_SIZE), but there should be no
+    emulation" variables (e.g., `QEMU_STACK_SIZE`), but there should be no
     reason to touch them.
 
-  - AFL_DEBUG will print the found entrypoint for the binary to stderr.
+  - `AFL_DEBUG` will print the found entrypoint for the binary to stderr.
     Use this if you are unsure if the entrypoint might be wrong - but
-    use it directly, e.g. afl-qemu-trace ./program
+    use it directly, e.g. `afl-qemu-trace ./program`
 
-  - AFL_ENTRYPOINT allows you to specify a specific entrypoint into the
+  - `AFL_ENTRYPOINT` allows you to specify a specific entrypoint into the
     binary (this can be very good for the performance!).
-    The entrypoint is specified as hex address, e.g. 0x4004110
+    The entrypoint is specified as hex address, e.g. `0x4004110`
     Note that the address must be the address of a basic block.
 
   - When the target is i386/x86_64 you can specify the address of the function
     that has to be the body of the persistent loop using
-    AFL_QEMU_PERSISTENT_ADDR=`start addr`.
+    `AFL_QEMU_PERSISTENT_ADDR=start addr`.
 
   - Another modality to execute the persistent loop is to specify also the
-    AFL_QEMU_PERSISTENT_RET=`end addr` env variable.
+    `AFL_QEMU_PERSISTENT_RET=end addr` env variable.
     With this variable assigned, instead of patching the return address, the
     specified instruction is transformed to a jump towards `start addr`.
 
-  - AFL_QEMU_PERSISTENT_GPR=1 QEMU will save the original value of general
+  - `AFL_QEMU_PERSISTENT_GPR=1` QEMU will save the original value of general
     purpose registers and restore them in each persistent cycle.
 
-  - With AFL_QEMU_PERSISTENT_RETADDR_OFFSET you can specify the offset from the
+  - With `AFL_QEMU_PERSISTENT_RETADDR_OFFSET` you can specify the offset from the
     stack pointer in which QEMU can find the return address when `start addr` is
-    hitted.
+    hit.
 
 ## 6) Settings for afl-cmin
 
 The corpus minimization script offers very little customization:
 
-  - Setting AFL_PATH offers a way to specify the location of afl-showmap
-    and afl-qemu-trace (the latter only in -Q mode).
+  - Setting `AFL_PATH` offers a way to specify the location of afl-showmap
+    and afl-qemu-trace (the latter only in `-Q` mode).
 
-  - AFL_KEEP_TRACES makes the tool keep traces and other metadata used for
+  - `AFL_KEEP_TRACES` makes the tool keep traces and other metadata used for
     minimization and normally deleted at exit. The files can be found in the
-    <out_dir>/.traces/*.
+    `<out_dir>/.traces/` directory.
 
-  - AFL_ALLOW_TMP permits this and some other scripts to run in /tmp. This is
+  - `AFL_ALLOW_TMP` permits this and some other scripts to run in /tmp. This is
     a modest security risk on multi-user systems with rogue users, but should
     be safe on dedicated fuzzing boxes.
 
 # #6) Settings for afl-tmin
 
-Virtually nothing to play with. Well, in QEMU mode (-Q), AFL_PATH will be
-searched for afl-qemu-trace. In addition to this, TMPDIR may be used if a
+Virtually nothing to play with. Well, in QEMU mode (`-Q`), `AFL_PATH` will be
+searched for afl-qemu-trace. In addition to this, `TMPDIR` may be used if a
 temporary file can't be created in the current working directory.
 
-You can specify AFL_TMIN_EXACT if you want afl-tmin to require execution paths
+You can specify `AFL_TMIN_EXACT` if you want afl-tmin to require execution paths
 to match when minimizing crashes. This will make minimization less useful, but
 may prevent the tool from "jumping" from one crashing condition to another in
-very buggy software. You probably want to combine it with the -e flag.
+very buggy software. You probably want to combine it with the `-e` flag.
 
 ## 8) Settings for afl-analyze
 
-You can set AFL_ANALYZE_HEX to get file offsets printed as hexadecimal instead
+You can set `AFL_ANALYZE_HEX` to get file offsets printed as hexadecimal instead
 of decimal.
 
 ## 9) Settings for libdislocator
 
 The library honors these environmental variables:
 
-  - AFL_LD_LIMIT_MB caps the size of the maximum heap usage permitted by the
+  - `AFL_LD_LIMIT_MB` caps the size of the maximum heap usage permitted by the
     library, in megabytes. The default value is 1 GB. Once this is exceeded,
     allocations will return NULL.
 
-  - AFL_LD_HARD_FAIL alters the behavior by calling abort() on excessive
-    allocations, thus causing what AFL would perceive as a crash. Useful for
+  - `AFL_LD_HARD_FAIL` alters the behavior by calling `abort()` on excessive
+    allocations, thus causing what AFL++ would perceive as a crash. Useful for
     programs that are supposed to maintain a specific memory footprint.
 
-  - AFL_LD_VERBOSE causes the library to output some diagnostic messages
+  - `AFL_LD_VERBOSE` causes the library to output some diagnostic messages
     that may be useful for pinpointing the cause of any observed issues.
 
-  - AFL_LD_NO_CALLOC_OVER inhibits abort() on calloc() overflows. Most
+  - `AFL_LD_NO_CALLOC_OVER` inhibits `abort()` on `calloc()` overflows. Most
     of the common allocators check for that internally and return NULL, so
     it's a security risk only in more exotic setups.
 
-  - AFL_ALIGNED_ALLOC=1 will force the alignment of the allocation size to
-    max_align_t to be compliant with the C standard.
+  - `AFL_ALIGNED_ALLOC=1` will force the alignment of the allocation size to
+    `max_align_t` to be compliant with the C standard.
 
 ## 10) Settings for libtokencap
 
-This library accepts AFL_TOKEN_FILE to indicate the location to which the
+This library accepts `AFL_TOKEN_FILE` to indicate the location to which the
 discovered tokens should be written.
 
 ## 11) Third-party variables set by afl-fuzz & other tools
@@ -526,33 +527,33 @@ discovered tokens should be written.
 Several variables are not directly interpreted by afl-fuzz, but are set to
 optimal values if not already present in the environment:
 
-  - By default, LD_BIND_NOW is set to speed up fuzzing by forcing the
+  - By default, `LD_BIND_NOW` is set to speed up fuzzing by forcing the
     linker to do all the work before the fork server kicks in. You can
-    override this by setting LD_BIND_LAZY beforehand, but it is almost
+    override this by setting `LD_BIND_LAZY` beforehand, but it is almost
     certainly pointless.
 
-  - By default, ASAN_OPTIONS are set to:
-
+  - By default, `ASAN_OPTIONS` are set to:
+```
     abort_on_error=1
     detect_leaks=0
     malloc_context_size=0
     symbolize=0
     allocator_may_return_null=1
-
-    If you want to set your own options, be sure to include abort_on_error=1 -
+```
+  If you want to set your own options, be sure to include `abort_on_error=1` -
     otherwise, the fuzzer will not be able to detect crashes in the tested
-    app. Similarly, include symbolize=0, since without it, AFL may have
+    app. Similarly, include `symbolize=0`, since without it, AFL++ may have
     difficulty telling crashes and hangs apart.
 
-  - In the same vein, by default, MSAN_OPTIONS are set to:
-
+  - In the same vein, by default, `MSAN_OPTIONS` are set to:
+```
     exit_code=86 (required for legacy reasons)
     abort_on_error=1
     symbolize=0
     msan_track_origins=0
     allocator_may_return_null=1
-
-    Be sure to include the first one when customizing anything, since some
-    MSAN versions don't call abort() on error, and we need a way to detect
+```
+  Be sure to include the first one when customizing anything, since some
+    MSAN versions don't call `abort()` on error, and we need a way to detect
     faults.