Thread: Help With Dynamically Allocated Stack

First things first, please post your code as plain text next time, so the forum can do it's syntax highlighting and line numbering.

Second, always compile with your warnings set to maximum. When I do that with the code you provided:

Code:

$ make foo
gcc -g -Wall -std=c99 -o foo foo.c -lpthread -lm -lpq
foo.c:27:6: error: conflicting types for ‘inputString’
foo.c:12:6: note: previous declaration of ‘inputString’ was here
foo.c: In function ‘inputString’:
foo.c:30:5: warning: passing argument 1 of ‘gets’ from incompatible pointer type [enabled by default]
/usr/include/stdio.h:634:14: note: expected ‘char *’ but argument is of type ‘char **’
foo.c: In function ‘creatStack’:
foo.c:37:10: error: conflicting types for ‘newstk’
foo.c:36:11: note: previous declaration of ‘newstk’ was here
foo.c:37:5: warning: implicit declaration of function ‘malloc’ [-Wimplicit-function-declaration]
foo.c:37:20: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default]
foo.c:37:20: warning: initialization makes integer from pointer without a cast [enabled by default]
foo.c:38:14: warning: comparison between pointer and integer [enabled by default]
foo.c:41:19: error: incompatible types when assigning to type ‘char *[20]’ from type ‘char’
foo.c: In function ‘evalOperand’:
foo.c:57:9: warning: implicit declaration of function ‘isdigit’ [-Wimplicit-function-declaration]
foo.c:59:13: error: ‘data’ undeclared (first use in this function)
foo.c:59:13: note: each undeclared identifier is reported only once for each function it appears in
foo.c:66:13: error: too few arguments to function ‘push’
foo.c:14:6: note: declared here
foo.c:72:13: error: too few arguments to function ‘pop’
foo.c:15:6: note: declared here
foo.c:73:13: error: too few arguments to function ‘pop’
foo.c:15:6: note: declared here
foo.c:80:21: warning: passing argument 1 of ‘push’ makes pointer from integer without a cast [enabled by default]
foo.c:14:6: note: expected ‘struct STAK *’ but argument is of type ‘int’
foo.c:80:21: error: too few arguments to function ‘push’
foo.c:14:6: note: declared here
foo.c:84:21: warning: passing argument 1 of ‘push’ makes pointer from integer without a cast [enabled by default]
foo.c:14:6: note: expected ‘struct STAK *’ but argument is of type ‘int’
foo.c:84:21: error: too few arguments to function ‘push’
foo.c:14:6: note: declared here
foo.c:88:21: warning: passing argument 1 of ‘push’ makes pointer from integer without a cast [enabled by default]
foo.c:14:6: note: expected ‘struct STAK *’ but argument is of type ‘int’
foo.c:88:21: error: too few arguments to function ‘push’
foo.c:14:6: note: declared here
foo.c:92:21: warning: passing argument 1 of ‘push’ makes pointer from integer without a cast [enabled by default]
foo.c:14:6: note: expected ‘struct STAK *’ but argument is of type ‘int’
foo.c:92:21: error: too few arguments to function ‘push’
foo.c:14:6: note: declared here
foo.c:98:5: error: incompatible type for argument 1 of ‘isFull’
foo.c:17:6: note: expected ‘int’ but argument is of type ‘STAK’
foo.c:102:9: warning: implicit declaration of function ‘getch’ [-Wimplicit-function-declaration]
foo.c:103:9: warning: implicit declaration of function ‘exit’ [-Wimplicit-function-declaration]
foo.c:103:9: warning: incompatible implicit declaration of built-in function ‘exit’ [enabled by default]
foo.c:113:13: error: ‘ret’ undeclared (first use in this function)
foo.c:115:13: error: ‘bin’ undeclared (first use in this function)
foo.c:118:5: warning: implicit declaration of function ‘dispRes’ [-Wimplicit-function-declaration]
foo.c:48:19: warning: unused variable ‘tnum’ [-Wunused-variable]
foo.c: At top level:
foo.c:121:6: error: conflicting types for ‘isFull’
foo.c:17:6: note: previous declaration of ‘isFull’ was here
foo.c: In function ‘push’:
foo.c:128:28: warning: assignment makes pointer from integer without a cast [enabled by default]
foo.c: At top level:
foo.c:131:5: error: conflicting types for ‘pop’
foo.c:15:6: note: previous declaration of ‘pop’ was here
foo.c: In function ‘pop’:
foo.c:134:7: warning: assignment makes integer from pointer without a cast [enabled by default]
make: *** [foo] Error 1

That's a whole lot of errors. Basically, this is the result of mashing together random pieces of code and hoping it works.

Your best bet is to toss this code, put away the keyboard, and get out the paper and pencil. Work through several small examples by hand until you understand how to solve the problem. Pay attention to every little step, as that will become the basis for your algorithm. When you have it all figured out, write your algorithm in pseudo code. Convert that pseudo code to real code, in small chunks. By small, I mean 5-10 lines at a time. Compile (at max warning level) every time you finish a chunk. Fix all errors/warnings, then test your code. Fix any bugs and do not move on to the next chunk until all previous code is 100% working and error free.

To address the bulk of the errors above, your function prototype, definition, and anywhere you call it must match in return type, and in the number, order and type of parameters.

EDIT
* You need to #include the right headers for the functions you're using. stdlib.h for malloc, free and exit; and ctype.h for isdigit.
* getch is non-standard, I suggest using getchar instead.
* You need to declare ret and bin and any other functions/variables you plan on using.