Here is readCommandLine
Thank you againCode:char * readCommandLine() { char command[100]; char *p; char *q; char *input; int i; fgets( command, sizeof( command ), stdin ); if ((p = strchr(command, '\n')) != NULL) *p = '\0'; input = command; i=0; while (input[i] != '\0') { history[historyCount][i] = input[i]; i++; } history[historyCount][i] = ' '; historyCount++; return(input); }
You're returning a pointer to a local variable (which ceases to exist at the point you return)
Disguising it as
input = command;
doesn't help
This would be a quick fix
static char command[100];
A better fix would be to pass the command array as a parameter, then you don't have to worry about allocating it locally
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
Also, your history[] array isn't being nul terminated, so you won't be able to use it as a string.
When all else fails, read the instructions.
If you're posting code, use code tags: [code] /* insert code here */ [/code]
When I delcare command as static it hangs my program..... It appears to hang on the fgets. If I put a printf before it it will print but if I put one after it, it won't get there. Any Ideas?
here is my edited code:
Thank you.Code:char * readCommandLine() { static char command[100]; char *p; char *q; char *input; int i; fgets( command, sizeof( command ), stdin ); if ((p = strchr(command, '\n')) != NULL) *p = '\0'; //input = command; i=0; while (command[i] != '\0') { history[historyCount][i] = command[i]; commandLine[i] = command[i]; i++; } history[historyCount][i] = ' '; historyCount++; return command; }
Here's a working version for you:
Code:#include <stdio.h> #include <string.h> char history[100][100]; int historyCount; char *readCommandLine(void) { static char command[100]; char *p; if (fgets( command, sizeof( command ), stdin )) { if ((p = strchr(command, '\n')) != NULL) { *p = '\0'; } strcpy(history[historyCount], command); historyCount++; return command; } return NULL; } int main(void) { char *cmdLine; int i; while ((cmdLine = readCommandLine()) != NULL && strcmp(cmdLine, "quit") != 0) { printf ("You entered command: >%s<\n", cmdLine); } for (i = 0; i < historyCount; i++) { printf ("Command history %d >%s<\n", i, history[i]); } return 0; } /* Output: this is a command You entered command: >this is a command< blah blah You entered command: >blah blah< quit Command history 0 >this is a command< Command history 1 >blah blah< Command history 2 >quit< */
When all else fails, read the instructions.
If you're posting code, use code tags: [code] /* insert code here */ [/code]
