Fix bugs in 1990/theorem

In this case these were not features.

The most important bug fix actually prevented the entry from working
properly: the generated code for the Fibonacci sequence just printed 0
over and over again. Added a segfault prevention here as it seemed like
if I'm going to fix it I might as well fix it properly. Removed this bug
from bugs.md.

A set of possible issues with the char m[][] array was also including
the size limit in the fgets() calls (that was my fault due to missing
the proper type of m at the time). Still might be good to test with
longer lines of input. Commands with known output are correct
nonetheless.

The other bug was due to the gets() to fgets() change where blank lines
were added where they shouldn't be. Now one can do ls | ./sorter and get
no blank lines after each file in the listing.
This commit is contained in:
Cody Boone Ferguson committed 2023-04-08 08:28:38 -07:00
1 parent 9161664f81
commit 15f61c58db
4 files changed
+22 -19

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+2
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@@ -3,3 +3,5 @@ fibonacci.c
mariano
sorter
sorter.c
theorem_bkp
theorem_bkp.c
+13 -7
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@@ -11,13 +11,19 @@ USA
make all
[Cody Boone Ferguson](/winners.html#Cody_Boone_Ferguson) fixed some segfaults
under modern (and in some cases earlier) systems with this entry. Originally we
noted that the 4 trailing args '0 0 0 0' were required on systems that dump core
when NULL is dereferenced but this problem showed itself in modern systems even
with the 4 '0 0 0 0'. Finally he changed this program to use `fgets()` not
`gets()` to make it safer and to prevent a warning about `gets()` at linking or
runtime. Thank you Cody for your assistance!
[Cody Boone Ferguson](/winners.html#Cody_Boone_Ferguson) fixed some bugs that
impacted the usability of this program including some segfaults under modern
systems (and possibly in some cases earlier systems) with this entry.
Originally we noted that the 4 trailing args '0 0 0 0' were required on systems
that dump core when NULL is dereferenced but this problem showed itself in
modern systems even with the 4 '0 0 0 0'. He also fixed the code so that the
generated `fibonacci.c` actually works; before it just printed `0` over and over
again (since it did not work anyway a segfault prevention was added here). He
also some array addressing (some of which might not be strictly necessary but as
he was testing the `fibonacci.c` bug he ended up changing it anyway). Finally he
changed this program to use `fgets()` not `gets()` to make it safer and to
prevent a warning about `gets()` at linking or runtime. Thank you Cody for your
assistance!
[Yusuke Endoh](/winners.html#Yusuke_Endoh) pointed out that `atof` nowadays
needs `#include <stdlib.h>` which was used in order to get this to work
+7 -7
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@@ -21,7 +21,7 @@ if(R=='/')*g/=u;
if(R=='^')P(g,*g,u);
C
w(g,R,u)float*g,u;char R;
/**/{int b,f;A=atoi(++a);b=atoi(++a);while((f=A+b)<15000){printf("%d\n",f);A=b;b=f;}}
/**/{int b,f;if(A>2){A=atoi(a[1]);b=atoi(a[2]);while((f=A+b)<15000){printf("%d\n",f);A=b;b=f;}}}
main(A,a)int A;char*a[];
o o
if(!strcmp(*++a,"-r"))S();
@@ -46,14 +46,14 @@ W=D=1;
;
while(W!=1)
o o
strcpy(j+m,v);
strcpy(j[m],v);
o
if((j-=W)<=W)break;
strcpy(j+m,m+j-W);
strcpy(j[m],m[j-W]);
C
while(strcmp(m+j-W,v)>0)
while(strcmp(m[j-W],v)>0)
j=i;
strcpy(v,i+m);
strcpy(v,i[m]);
C
for(i=(W/=3)-1;++i<n;)
;
@@ -78,12 +78,12 @@ return O;
for(j=0;j<n;puts(j++[m]));
e("",O,O,a);
n=j-(O=1);
while(fgets(j++[m],500,stdin));
while(fgets(j++[m],99,stdin))(j-1)[m][strlen((j-1)[m])-1]='\0';
if(!strcmp(++a,"-r"))S();
C
/**/main(A,a)int A;char*a[];
Y
S(){while(fgets(b++[m],500,stdin));for(b--;b--;puts(b[m]));}
S(){while(fgets(b++[m],99,stdin))(b-1)[m][strlen((b-1)[m])-1]='\0';for(b--;b--;puts(b[m]));}
char*f,m[500][99],R,v[99];
int b,W,n,i,j,z;
float Q,G,D,M,T,O,B,U,V,N,e();
-5
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@@ -476,11 +476,6 @@ so it should stay with this note.
this entry that prevented it from working. However if not enough args are
specified this program will crash. This should NOT be fixed.
## STATUS: known bug - please help us fix
On the other hand the `fibonacci` program that is generated prints a string of
0s over and over again. Can you fix this? See the README.md for details on how
to generate it.
# 1991