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| -rw-r--r-- | doc/ChangeLog | 8 | ||||
| -rw-r--r-- | doc/gawk.info | 69 | ||||
| -rw-r--r-- | doc/gawk.texi | 62 | ||||
| -rw-r--r-- | doc/gawktexi.in | 62 |
4 files changed, 106 insertions, 95 deletions
diff --git a/doc/ChangeLog b/doc/ChangeLog index c93a266f..620ad769 100644 --- a/doc/ChangeLog +++ b/doc/ChangeLog @@ -1,6 +1,12 @@ +2014-09-02 Arnold D. Robbins <arnold@skeeve.com> + + * gawktexi.in: Corrections to walkthrough in debugger chapter. + Thanks to David "bamber" Ward <dlward134@gmail.com> for + the problem report. + 2014-09-01 Arnold D. Robbins <arnold@skeeve.com> - * gaktexi.in: Add index entry for @ - @load, @include, + * gawktexi.in: Add index entry for @ - @load, @include, and indirect function calls. Thanks to "Kenny McKormack" in comp.lang.awk. diff --git a/doc/gawk.info b/doc/gawk.info index 8d71f77c..c8212732 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -20524,7 +20524,7 @@ options. (`gawk' is not designed to debug command-line programs, only programs contained in files.) In our case, we invoke the debugger like this: - $ gawk -D -f getopt.awk -f join.awk -f uniq.awk inputfile + $ gawk -D -f getopt.awk -f join.awk -f uniq.awk -1 inputfile where both `getopt.awk' and `uniq.awk' are in `$AWKPATH'. (Experienced users of GDB or similar debuggers should note that this syntax is @@ -20576,7 +20576,7 @@ for a breakpoint in `uniq.awk' is at the beginning of the function To set the breakpoint, use the `b' (breakpoint) command: gawk> b are_equal - -| Breakpoint 1 set at file `awklib/eg/prog/uniq.awk', line 64 + -| Breakpoint 1 set at file `awklib/eg/prog/uniq.awk', line 63 The debugger tells us the file and line number where the breakpoint is. Now type `r' or `run' and the program runs until it hits the @@ -20586,8 +20586,8 @@ breakpoint for the first time: -| Starting program: -| Stopping in Rule ... -| Breakpoint 1, are_equal(n, m, clast, cline, alast, aline) - at `awklib/eg/prog/uniq.awk':64 - -| 64 if (fcount == 0 && charcount == 0) + at `awklib/eg/prog/uniq.awk':63 + -| 63 if (fcount == 0 && charcount == 0) gawk> Now we can look at what's going on inside our program. First of all, @@ -20597,11 +20597,11 @@ the current stack frames: gawk> bt -| #0 are_equal(n, m, clast, cline, alast, aline) - at `awklib/eg/prog/uniq.awk':69 - -| #1 in main() at `awklib/eg/prog/uniq.awk':89 + at `awklib/eg/prog/uniq.awk':68 + -| #1 in main() at `awklib/eg/prog/uniq.awk':88 This tells us that `are_equal()' was called by the main program at -line 89 of `uniq.awk'. (This is not a big surprise, since this is the +line 88 of `uniq.awk'. (This is not a big surprise, since this is the only call to `are_equal()' in the program, but in more complex programs, knowing who called a function and with what parameters can be the key to finding the source of the problem.) @@ -20620,13 +20620,13 @@ function was called without arguments (*note Function Calls::). A more useful variable to display might be the current record: gawk> p $0 - -| $0 = string ("gawk is a wonderful program!") + -| $0 = "gawk is a wonderful program!" This might be a bit puzzling at first since this is the second line of our test input above. Let's look at `NR': gawk> p NR - -| NR = number (2) + -| NR = 2 So we can see that `are_equal()' was only called for the second record of the file. Of course, this is because our program contains a rule for @@ -20640,7 +20640,7 @@ of the file. Of course, this is because our program contains a rule for OK, let's just check that that rule worked correctly: gawk> p last - -| last = string ("awk is a wonderful program!") + -| last = "awk is a wonderful program!" Everything we have done so far has verified that the program has worked as planned, up to and including the call to `are_equal()', so @@ -20649,38 +20649,39 @@ must begin "stepping through" the lines of `are_equal()'. We start by typing `n' (for "next"): gawk> n - -| 67 if (fcount > 0) { + -| 66 if (fcount > 0) { - This tells us that `gawk' is now ready to execute line 67, which + This tells us that `gawk' is now ready to execute line 66, which decides whether to give the lines the special "field skipping" treatment -indicated by the `-f' command-line option. (Notice that we skipped -from where we were before at line 64 to here, since the condition in -line 64 `if (fcount == 0 && charcount == 0)' was false.) +indicated by the `-1' command-line option. (Notice that we skipped +from where we were before at line 63 to here, since the condition in +line 63 `if (fcount == 0 && charcount == 0)' was false.) Continuing to step, we now get to the splitting of the current and last records: gawk> n - -| 68 n = split(last, alast) + -| 67 n = split(last, alast) gawk> n - -| 69 m = split($0, aline) + -| 68 m = split($0, aline) At this point, we should be curious to see what our records were split into, so we try to look: gawk> p n m alast aline - -| n = number (5) - -| m = number (5) + -| n = 5 + -| m = untyped variable -| alast = array, 5 elements - -| aline = array, 5 elements + -| aline = untyped variable (The `p' command can take more than one argument, similar to `awk''s `print' statement.) This is kind of disappointing, though. All we found out is that -there are five elements in each of our arrays. Useful enough (we now -know that none of the words were accidentally left out), but what if we -want to see inside the array? +there are five elements in `alast'; `m' and `aline' don't have values +yet since we are at line 68 but haven't executed it yet. This +information is useful enough (we now know that none of the words were +accidentally left out), but what if we want to see inside the array? The first choice would be to use subscripts: @@ -20690,25 +20691,25 @@ want to see inside the array? Oops! gawk> p alast[1] - -| alast["1"] = string ("awk") + -| alast["1"] = "awk" This would be kind of slow for a 100-member array, though, so `gawk' provides a shortcut (reminiscent of another language not to be mentioned): gawk> p @alast - -| alast["1"] = string ("awk") - -| alast["2"] = string ("is") - -| alast["3"] = string ("a") - -| alast["4"] = string ("wonderful") - -| alast["5"] = string ("program!") + -| alast["1"] = "awk" + -| alast["2"] = "is" + -| alast["3"] = "a" + -| alast["4"] = "wonderful" + -| alast["5"] = "program!" It looks like we got this far OK. Let's take another step or two: gawk> n - -| 70 clast = join(alast, fcount, n) + -| 69 clast = join(alast, fcount, n) gawk> n - -| 71 cline = join(aline, fcount, m) + -| 70 cline = join(aline, fcount, m) Well, here we are at our error (sorry to spoil the suspense). What we had in mind was to join the fields starting from the second one to @@ -20716,8 +20717,8 @@ make the virtual record to compare, and if the first field was numbered zero, this would work. Let's look at what we've got: gawk> p cline clast - -| cline = string ("gawk is a wonderful program!") - -| clast = string ("awk is a wonderful program!") + -| cline = "gawk is a wonderful program!" + -| clast = "awk is a wonderful program!" Hey, those look pretty familiar! They're just our original, unaltered, input records. A little thinking (the human brain is still @@ -34386,7 +34387,7 @@ Node: Debugging Terms825200 Node: Awk Debugging827797 Node: Sample Debugging Session828689 Node: Debugger Invocation829209 -Node: Finding The Bug830542 +Node: Finding The Bug830545 Node: List of Debugger Commands837024 Node: Breakpoint Control838356 Node: Debugger Execution Control842020 diff --git a/doc/gawk.texi b/doc/gawk.texi index 6226e735..7078a70e 100644 --- a/doc/gawk.texi +++ b/doc/gawk.texi @@ -28682,7 +28682,7 @@ to debug command-line programs, only programs contained in files.) In our case, we invoke the debugger like this: @example -$ @kbd{gawk -D -f getopt.awk -f join.awk -f uniq.awk inputfile} +$ @kbd{gawk -D -f getopt.awk -f join.awk -f uniq.awk -1 inputfile} @end example @noindent @@ -28744,7 +28744,7 @@ the breakpoint, use the @code{b} (breakpoint) command: @example gawk> @kbd{b are_equal} -@print{} Breakpoint 1 set at file `awklib/eg/prog/uniq.awk', line 64 +@print{} Breakpoint 1 set at file `awklib/eg/prog/uniq.awk', line 63 @end example The debugger tells us the file and line number where the breakpoint is. @@ -28756,8 +28756,8 @@ gawk> @kbd{r} @print{} Starting program: @print{} Stopping in Rule ... @print{} Breakpoint 1, are_equal(n, m, clast, cline, alast, aline) - at `awklib/eg/prog/uniq.awk':64 -@print{} 64 if (fcount == 0 && charcount == 0) + at `awklib/eg/prog/uniq.awk':63 +@print{} 63 if (fcount == 0 && charcount == 0) gawk> @end example @@ -28769,12 +28769,12 @@ listing of the current stack frames: @example gawk> @kbd{bt} @print{} #0 are_equal(n, m, clast, cline, alast, aline) - at `awklib/eg/prog/uniq.awk':69 -@print{} #1 in main() at `awklib/eg/prog/uniq.awk':89 + at `awklib/eg/prog/uniq.awk':68 +@print{} #1 in main() at `awklib/eg/prog/uniq.awk':88 @end example This tells us that @code{are_equal()} was called by the main program at -line 89 of @file{uniq.awk}. (This is not a big surprise, since this +line 88 of @file{uniq.awk}. (This is not a big surprise, since this is the only call to @code{are_equal()} in the program, but in more complex programs, knowing who called a function and with what parameters can be the key to finding the source of the problem.) @@ -28798,7 +28798,7 @@ A more useful variable to display might be the current record: @example gawk> @kbd{p $0} -@print{} $0 = string ("gawk is a wonderful program!") +@print{} $0 = "gawk is a wonderful program!" @end example @noindent @@ -28807,7 +28807,7 @@ our test input above. Let's look at @code{NR}: @example gawk> @kbd{p NR} -@print{} NR = number (2) +@print{} NR = 2 @end example @noindent @@ -28826,7 +28826,7 @@ OK, let's just check that that rule worked correctly: @example gawk> @kbd{p last} -@print{} last = string ("awk is a wonderful program!") +@print{} last = "awk is a wonderful program!" @end example Everything we have done so far has verified that the program has worked as @@ -28837,13 +28837,13 @@ be inside this function. To investigate further, we must begin @example gawk> @kbd{n} -@print{} 67 if (fcount > 0) @{ +@print{} 66 if (fcount > 0) @{ @end example -This tells us that @command{gawk} is now ready to execute line 67, which +This tells us that @command{gawk} is now ready to execute line 66, which decides whether to give the lines the special ``field skipping'' treatment -indicated by the @option{-f} command-line option. (Notice that we skipped -from where we were before at line 64 to here, since the condition in line 64 +indicated by the @option{-1} command-line option. (Notice that we skipped +from where we were before at line 63 to here, since the condition in line 63 @samp{if (fcount == 0 && charcount == 0)} was false.) Continuing to step, we now get to the splitting of the current and @@ -28851,9 +28851,9 @@ last records: @example gawk> @kbd{n} -@print{} 68 n = split(last, alast) +@print{} 67 n = split(last, alast) gawk> @kbd{n} -@print{} 69 m = split($0, aline) +@print{} 68 m = split($0, aline) @end example At this point, we should be curious to see what our records were split @@ -28861,10 +28861,10 @@ into, so we try to look: @example gawk> @kbd{p n m alast aline} -@print{} n = number (5) -@print{} m = number (5) +@print{} n = 5 +@print{} m = untyped variable @print{} alast = array, 5 elements -@print{} aline = array, 5 elements +@print{} aline = untyped variable @end example @noindent @@ -28872,7 +28872,9 @@ gawk> @kbd{p n m alast aline} @command{awk}'s @code{print} statement.) This is kind of disappointing, though. All we found out is that there -are five elements in each of our arrays. Useful enough (we now know that +are five elements in @code{alast}; @code{m} and @code{aline} don't have +values yet since we are at line 68 but haven't executed it yet. +This information is useful enough (we now know that none of the words were accidentally left out), but what if we want to see inside the array? @@ -28888,7 +28890,7 @@ Oops! @example gawk> @kbd{p alast[1]} -@print{} alast["1"] = string ("awk") +@print{} alast["1"] = "awk" @end example This would be kind of slow for a 100-member array, though, so @@ -28897,11 +28899,11 @@ not to be mentioned): @example gawk> @kbd{p @@alast} -@print{} alast["1"] = string ("awk") -@print{} alast["2"] = string ("is") -@print{} alast["3"] = string ("a") -@print{} alast["4"] = string ("wonderful") -@print{} alast["5"] = string ("program!") +@print{} alast["1"] = "awk" +@print{} alast["2"] = "is" +@print{} alast["3"] = "a" +@print{} alast["4"] = "wonderful" +@print{} alast["5"] = "program!" @end example It looks like we got this far OK. Let's take another step @@ -28909,9 +28911,9 @@ or two: @example gawk> @kbd{n} -@print{} 70 clast = join(alast, fcount, n) +@print{} 69 clast = join(alast, fcount, n) gawk> @kbd{n} -@print{} 71 cline = join(aline, fcount, m) +@print{} 70 cline = join(aline, fcount, m) @end example Well, here we are at our error (sorry to spoil the suspense). What we @@ -28921,8 +28923,8 @@ this would work. Let's look at what we've got: @example gawk> @kbd{p cline clast} -@print{} cline = string ("gawk is a wonderful program!") -@print{} clast = string ("awk is a wonderful program!") +@print{} cline = "gawk is a wonderful program!" +@print{} clast = "awk is a wonderful program!" @end example Hey, those look pretty familiar! They're just our original, unaltered, diff --git a/doc/gawktexi.in b/doc/gawktexi.in index d7867c45..ebd1ce17 100644 --- a/doc/gawktexi.in +++ b/doc/gawktexi.in @@ -27780,7 +27780,7 @@ to debug command-line programs, only programs contained in files.) In our case, we invoke the debugger like this: @example -$ @kbd{gawk -D -f getopt.awk -f join.awk -f uniq.awk inputfile} +$ @kbd{gawk -D -f getopt.awk -f join.awk -f uniq.awk -1 inputfile} @end example @noindent @@ -27842,7 +27842,7 @@ the breakpoint, use the @code{b} (breakpoint) command: @example gawk> @kbd{b are_equal} -@print{} Breakpoint 1 set at file `awklib/eg/prog/uniq.awk', line 64 +@print{} Breakpoint 1 set at file `awklib/eg/prog/uniq.awk', line 63 @end example The debugger tells us the file and line number where the breakpoint is. @@ -27854,8 +27854,8 @@ gawk> @kbd{r} @print{} Starting program: @print{} Stopping in Rule ... @print{} Breakpoint 1, are_equal(n, m, clast, cline, alast, aline) - at `awklib/eg/prog/uniq.awk':64 -@print{} 64 if (fcount == 0 && charcount == 0) + at `awklib/eg/prog/uniq.awk':63 +@print{} 63 if (fcount == 0 && charcount == 0) gawk> @end example @@ -27867,12 +27867,12 @@ listing of the current stack frames: @example gawk> @kbd{bt} @print{} #0 are_equal(n, m, clast, cline, alast, aline) - at `awklib/eg/prog/uniq.awk':69 -@print{} #1 in main() at `awklib/eg/prog/uniq.awk':89 + at `awklib/eg/prog/uniq.awk':68 +@print{} #1 in main() at `awklib/eg/prog/uniq.awk':88 @end example This tells us that @code{are_equal()} was called by the main program at -line 89 of @file{uniq.awk}. (This is not a big surprise, since this +line 88 of @file{uniq.awk}. (This is not a big surprise, since this is the only call to @code{are_equal()} in the program, but in more complex programs, knowing who called a function and with what parameters can be the key to finding the source of the problem.) @@ -27896,7 +27896,7 @@ A more useful variable to display might be the current record: @example gawk> @kbd{p $0} -@print{} $0 = string ("gawk is a wonderful program!") +@print{} $0 = "gawk is a wonderful program!" @end example @noindent @@ -27905,7 +27905,7 @@ our test input above. Let's look at @code{NR}: @example gawk> @kbd{p NR} -@print{} NR = number (2) +@print{} NR = 2 @end example @noindent @@ -27924,7 +27924,7 @@ OK, let's just check that that rule worked correctly: @example gawk> @kbd{p last} -@print{} last = string ("awk is a wonderful program!") +@print{} last = "awk is a wonderful program!" @end example Everything we have done so far has verified that the program has worked as @@ -27935,13 +27935,13 @@ be inside this function. To investigate further, we must begin @example gawk> @kbd{n} -@print{} 67 if (fcount > 0) @{ +@print{} 66 if (fcount > 0) @{ @end example -This tells us that @command{gawk} is now ready to execute line 67, which +This tells us that @command{gawk} is now ready to execute line 66, which decides whether to give the lines the special ``field skipping'' treatment -indicated by the @option{-f} command-line option. (Notice that we skipped -from where we were before at line 64 to here, since the condition in line 64 +indicated by the @option{-1} command-line option. (Notice that we skipped +from where we were before at line 63 to here, since the condition in line 63 @samp{if (fcount == 0 && charcount == 0)} was false.) Continuing to step, we now get to the splitting of the current and @@ -27949,9 +27949,9 @@ last records: @example gawk> @kbd{n} -@print{} 68 n = split(last, alast) +@print{} 67 n = split(last, alast) gawk> @kbd{n} -@print{} 69 m = split($0, aline) +@print{} 68 m = split($0, aline) @end example At this point, we should be curious to see what our records were split @@ -27959,10 +27959,10 @@ into, so we try to look: @example gawk> @kbd{p n m alast aline} -@print{} n = number (5) -@print{} m = number (5) +@print{} n = 5 +@print{} m = untyped variable @print{} alast = array, 5 elements -@print{} aline = array, 5 elements +@print{} aline = untyped variable @end example @noindent @@ -27970,7 +27970,9 @@ gawk> @kbd{p n m alast aline} @command{awk}'s @code{print} statement.) This is kind of disappointing, though. All we found out is that there -are five elements in each of our arrays. Useful enough (we now know that +are five elements in @code{alast}; @code{m} and @code{aline} don't have +values yet since we are at line 68 but haven't executed it yet. +This information is useful enough (we now know that none of the words were accidentally left out), but what if we want to see inside the array? @@ -27986,7 +27988,7 @@ Oops! @example gawk> @kbd{p alast[1]} -@print{} alast["1"] = string ("awk") +@print{} alast["1"] = "awk" @end example This would be kind of slow for a 100-member array, though, so @@ -27995,11 +27997,11 @@ not to be mentioned): @example gawk> @kbd{p @@alast} -@print{} alast["1"] = string ("awk") -@print{} alast["2"] = string ("is") -@print{} alast["3"] = string ("a") -@print{} alast["4"] = string ("wonderful") -@print{} alast["5"] = string ("program!") +@print{} alast["1"] = "awk" +@print{} alast["2"] = "is" +@print{} alast["3"] = "a" +@print{} alast["4"] = "wonderful" +@print{} alast["5"] = "program!" @end example It looks like we got this far OK. Let's take another step @@ -28007,9 +28009,9 @@ or two: @example gawk> @kbd{n} -@print{} 70 clast = join(alast, fcount, n) +@print{} 69 clast = join(alast, fcount, n) gawk> @kbd{n} -@print{} 71 cline = join(aline, fcount, m) +@print{} 70 cline = join(aline, fcount, m) @end example Well, here we are at our error (sorry to spoil the suspense). What we @@ -28019,8 +28021,8 @@ this would work. Let's look at what we've got: @example gawk> @kbd{p cline clast} -@print{} cline = string ("gawk is a wonderful program!") -@print{} clast = string ("awk is a wonderful program!") +@print{} cline = "gawk is a wonderful program!" +@print{} clast = "awk is a wonderful program!" @end example Hey, those look pretty familiar! They're just our original, unaltered, |