Using fscanf in C - c

I am trying to read from a file into array.
My file called Players.txt contains:
Del Piero|3|Italy|Juventus|
Ronaldo|0|Portugal|Real Madrit
I used fscanf , but it is not working correctly , I am not doing right the conversion.
can anyone help me to read and store them into arrays. Like the array player name to contain { Del Piero, Ronaldo}
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <stddef.h>
#include <ctype.h>
#define NUM_PLAYERS 20
#define NAME_LENGTH 100
#define COUNTRY_NAME 20
int main (void)
{
FILE *Players;
char player_name [NUM_PLAYERS][NAME_LENGTH] = {0};
char country_name[NUM_PLAYERS][COUNTRY_NAME] = {0};
char team_name[NUM_PLAYERS][NAME_LENGTH] = {0};
int goals_scored[NUM_PLAYERS] = {0};
int i;
Players = fopen("G:\\COP2220\\Project 5\\Players.txt", "r");
if (Players == NULL)
{
printf("File not found.\n");
}
else
{
while (fscanf(Players, " %[^|]s %[^|]d %[^|]s %[^|]s",player_name[i],&goals_scored[i],country_name[i],team_name[i]))
{
printf("The player %s, scored %d from %s plays in %s\n", player_name, goals_scored,country_name, team_name );
}
}
fclose(Players);
return 0;
}

[] is a type all in itself, you shouldn't append s or d at the its end. All you really have to do is change the format to this:
"%[^|] | %d | %[^|] | %[^|]|\n"
And consider changing your while loop to break when fscanf doesn't return 4.
Here's some working code:
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <stddef.h>
#include <ctype.h>
#define NUM_PLAYERS 20
#define NAME_LENGTH 100
#define COUNTRY_NAME 20
int
main (void)
{
FILE * Players;
char player_name [NUM_PLAYERS][NAME_LENGTH] = {0};
char country_name[NUM_PLAYERS][COUNTRY_NAME] = {0};
char team_name[NUM_PLAYERS][NAME_LENGTH] = {0};
int goals_scored[NUM_PLAYERS] = {0};
int i = 0, ret = 0;
Players = fopen("testfile", "r");
if (Players == NULL)
{
printf("File not found.\n");
}
else
{
for (;;)
{
ret = fscanf(Players, "%[^|] | %d | %[^|] | %[^|]|\n",
player_name[i],
&goals_scored[i],
country_name[i],
team_name[i]);
if (ret != 4)
{
printf ("only %d arguments were matched\n", ret);
break;
}
printf("The player %s, scored %d from %s plays in %s\n",
player_name[i],
goals_scored[i],
country_name[i],
team_name[i]);
i++;
}
fclose(Players);
}
return 0;
}

The scanf format %[^|]s reads a string of non-| characters followed by an s character, which can never match (since the next character after the string, if it exists, must be a |, not an s). You probably want something more like:
while (4 == fscanf(Players, " %99[^|\n]|%d| %19[^|\n]| %99[^|\n]", player_name[i], &goals_scored[i], country_name[i], team_name[i]))
Note the additional string size limits to avoid overflowing arrays, and the newlines in the patterns, so that they can't be included in any of the strings (but can appear between strings).
Note also that this will match your second line, but will leave |Madrit to be read by the next call to fscanf, so you might want to put
fscanf(Players, "%*[\n]%*c");
in the loop to read the rest of the line up to the newline and throw it away.

You never actually consume the "|" characters in between your fields. Instead you're only reading up until the "|" character. Try adjusting your format string to something like:
"%[^|]|%[^|]d|%[^|]|%[^|]"

Your format scan string is incorrect. The %[..] is itself the format specifier, adding the s or d after it is just taken to be a literal s or d in the scan string, and not a %s or %d like you are expecting.
Also, your printf() prints out the goals_scored address rather than the stored value for the player. You forgot to index the array.
It is possible to get your format scan string to work, but since the last field appears optional, you have some complexity to deal with that case. In the code below, we deal with this by explicitly calling out that the newline should not be part of the last field. Then the %*c will discard either the | or the \n at the end. The space at the end of the scan string allows fscanf() to move to the next line in the case that the | was discarded.
while (fscanf(Players, " %[^|]|%d|%[^|]|%[^|\n]%*c ",
player_name[i], &goals_scored[i], country_name[i], team_name[i]) == 4)
{
printf("The player %s, scored %d from %s plays in %s\n",
player_name, goals_scored[i], country_name, team_name);
}
However, this problem seems ideal for strtok(). The advantage is that you have more control over how to deal with each field, and you can get more information about where errors are occurring during a parse of the line.
int parse_line (char *buffer,
char *name, int *goals, char *country, char *team,
char **rest)
{
char *tok = strtok(buffer, "|");
int count = 0;
while (tok && count < 4) {
++count;
switch (count) {
case 1: strcpy(name, tok); break;
case 2: *goals = atoi(tok); break;
case 3: strcpy(country, tok); break;
case 4: strcpy(team, tok); break;
default: break;
}
tok = strtok(0, "|");
}
*rest = tok;
return count;
}
You would change your code to read in a line of data, and then feed that line to the parse_line() function.
char buf[MAX_LINE_LENGTH];
char *rest;
while (fgets(buf, sizeof(buf), Players) != 0) {
parse_line(buf,
player_name[i], &goals_scored[i], country_name[i], team_name[i],
&rest);
printf("The player %s, scored %d from %s plays in %s\n",
player_name, goals_scored[i], country_name, team_name);
}

Related

Get the text before and after strstr in C

I need to be able to extract the characters before and after a substring, currently I have the following code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, char *argv[]){
char *text = (char *) malloc (10000000);
char *word = argv[1];
int rep;
FILE *f;
if(argc < 2)
{
printf("Usage: GET <website> | ./word_counter <word>\n");
exit(1);
}
fread(text, 100, 10000000, stdin);
const char *tmp = text;
f = fopen("output.txt", "w");
fprintf(f, "%s\n", "REPS");
while(tmp = strstr(tmp, word)){
printf("%.50s\n", tmp);
rep++;
tmp++;
}
printf("Word count: %d\n", rep);
fclose(f);
system("gedit output.txt");
return 0;
}
I made a copy of the original input so I could leave it untouched and get the "before" characters from it.
Using strstr() on tmp (the original input copy) I can find the instances of the word I'm looking for and print the first 50 characters. But knowing this, how can I access the 50 characters BEFORE this instance?
Any help will be appreciated. Thanks!
Apart from the printing question itself, there are a couple of errors in your code. I have corrected most of them; a short list is:
Always test if malloc succeeded.
fread(text, 100, 10000000, ..) reads way too many text. 100 * 10000000 = 1000000000, almost a full gigabyte. You only allocated enough memory for 10 Mb.
You read from a text file and treat this data as a string. Therefore, you must make sure the data ends with a 0, else functions such as printf and strstr will try to continue reading after the end.
Your rep variable starts out uninitialized and therefore you will always see a random number.
Always free memory you allocated.
That said, it is slightly more efficient to use a dedicated function to print out text – if only to not put too much in your main. And since it's a function, you can add as many useful parameters into it as you want; I added before and after variables, so you can vary the number of characters shown.
For added niceness, this function prints a correct number of spaces when the phrase is found before the minimum number of before characters, so the results line up nicely. Also, since printing out characters such as tab and newlines will mess up your output, I replaced them with ?.
There is, admittedly, some repetition in print_range but in this case I went for clarity, rather than brevity.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_LENGTH 10000000
void print_range (char *source_text, int startindex, int before, int after, int phrase_length)
{
int i;
if (before > startindex)
{
for (i=0; i<before-startindex; i++)
printf (" ");
startindex = before;
}
for (i=0; i<before; i++)
{
if (strchr ("\t\r\n", source_text[startindex-before+i]))
printf ("?");
else
printf ("%c", source_text[startindex-before+i]);
}
for (i=0; i<phrase_length; i++)
{
if (strchr ("\t\r\n", source_text[startindex+i]))
printf ("?");
else
printf ("%c", source_text[startindex+i]);
}
for (i=0; i<after; i++)
{
if (!source_text[startindex+phrase_length+i])
break;
if (strchr ("\t\r\n", source_text[startindex+phrase_length+i]))
printf ("?");
else
printf ("%c", source_text[startindex+phrase_length+i]);
}
printf ("\n");
}
int main (int argc, char *argv[]){
char *text = (char *) malloc (MAX_LENGTH);
char *word = argv[1];
int rep = 0;
if (!text)
return -1;
if(argc < 2)
{
printf("Usage: GET <website> | ./word_counter <word>\n");
exit(1);
}
fread(text, 1, MAX_LENGTH, stdin);
text[MAX_LENGTH] = 0;
const char *tmp = text;
do
{
tmp = strstr(tmp, word);
if (!tmp)
break;
print_range (text, tmp-text, 16,16, strlen(word));
rep++;
tmp++;
} while (1);
free (text);
printf ("Word count: %d\n", rep);
return 0;
}
Result of running this on its own source code:
~/Documents $ ./wordcounter printf < wordcounter.c
tindex; i++)????printf (" ");???starti
-before+i]))????printf ("?");???else??
"?");???else????printf ("%c", source_t
before+i]);??}??printf ("{");??for (i=
rtindex+i]))????printf ("?");???else??
"?");???else????printf ("%c", source_t
tindex+i]);??}??printf ("}");??for (i=
_length+i]))????printf ("?");???else??
"?");???else????printf ("%c", source_t
length+i]);??}??printf ("\n");?}??int
argc < 2)??{??? printf("Usage: GET <we
?free (text);???printf ("Word count: %
Word count: 12

How to use set scanset in sscanf to read numbers like 0-9

How to read the input with scanset like[0-9] or [a-z] in sscanf function in C.We have not been able to successfully implement a scanset to scan through a string successfully.
This is my example:
void printResult(char * test, char * actual, char * expected)
{
printf("\n\n%d. %s\r",testcount++, test);
if(strcmp(actual,expected) == 0)
{
printf("SUCCESS\r");
printf("Output:%s", actual);
}
else
{
printf("FAILED\r");
printf("Expected Output:%s Actual Output:%s", expected, actual);
}
}
int main()
{
char buffer[] = "250MEL\r";
char * pBuffer = buffer;
char output[5]={0};
//1
sscanf(pBuffer,"%[ 0-9 ]s",output);
printResult("%[0-9]s", output, "250");
//2
sscanf(pBuffer,"%3[ 0-9 ]s",output);
printResult("%3[0-9]s", output, "250");
return 0;
}
can you anyone help me to use a scanset correctly.
TL;DR It isn't clear what makes you think your scan sets failed; they work OK in this context for me. The mildly modified code shown below demonstrates this.
As I noted in a comment, a scan set is of the form %[…] — it stops at the ] and anything following (s in the code in the question) is not part of the scan set. If you need to include ] in the scan set, it must be the first character (after the caret that negates a scan set, if you're using a negated scan set). With the s after the scan set, if the input includes an s after the end of the digit and blank sequence (the first blank in the scan set is significant; the second, being a repeat, is not), then that character will be 'consumed' and the next input operation would continue after the s; if the next character is not an s, then it is left in the input for the next input operation. Also, if the next character is not an s, the matching fails, but there is no way for sscanf() to report that when the scan set is the last or only conversion specification in the format string. Trailing context is always expendable; it's absence cannot be detected.
Your code is curious in that it uses \r in a number of places. You will seldom need to use \r in C code — you should use \n in your code (or blanks, or …).
Here's a program closely based on yours, with some changes. The code checks the return value from sscanf(); it replaces most of the carriage returns with some other character(s); it keeps the faulty format strings; it makes the argument to the print function match the argument to the sscanf() function.
#include <stdio.h>
#include <string.h>
static int testcount = 1;
static void printResult(char *test, char *actual, char *expected)
{
printf("\n\n%d. [%s]: ", testcount++, test);
if (strcmp(actual, expected) == 0)
{
printf("SUCCESS ");
printf("Output: [%s]\n", actual);
}
else
{
printf("FAILED ");
printf("Expected Output: [%s], Actual Output: [%s]\n", expected, actual);
}
}
int main(void)
{
char buffer[] = "250MEL\r";
char *pBuffer = buffer;
char output[5] = {0};
// 1
if (sscanf(pBuffer, "%[ 0-9 ]s", output) != 1)
printf("scanf() 1 failed\n");
printResult("%[ 0-9 ]s", output, "250");
// 2
if (sscanf(pBuffer, "%3[ 0-9 ]s", output) != 1)
printf("scanf() 1 failed\n");
printResult("%3[ 0-9 ]s", output, "250");
return 0;
}
It also produces the expected output:
1. [%[ 0-9 ]s]: SUCCESS Output: [250]
2. [%3[ 0-9 ]s]: SUCCESS Output: [250]
If you weren't seeing SUCCESS before, that's because the \r character moves the writing position to the start of the line, so what followed overwrote SUCCESS.
Auxilliary question
Also, please let me know how can I set a range for A-Z like below — but this is not working:
sscanf(pBuffer,"%*[A-Z]s",output);
printResult("%[A-Z]s",output, "MEL" );
Please pay attention!
Your comment is showing that you still think %[…]s is the notation for a scan set but the s is spurious; it is not part of the scan set notation. Stop thinking of %[…] as a modifier for %s; it isn't a modifier. It is a completely independent conversion specification, almost wholly unrelated to and syntactically quite distinct from %s. The square-bracket notation is also, categorically and unequivocally, not a part of any standard printf() conversion specification syntax.
Here is some revised code loosely based on the previous part of the answer (and hence on the code in the question). It isn't stellar, but it does show some useful information.
#include <stdio.h>
#include <string.h>
static int strings_match(const char *actual, const char *expected);
static void printResult(const char *format, const char *data, const char *act1,
char *exp1, const char *act2, char *exp2);
int main(void)
{
char buffer1[] = "250MEL#93";
char buffer2[] = " 250 \t\tMELabc";
char number[5] = "";
char letters[5] = "";
const char fmt1[] = "%4[0-9]%4[A-Z]";
const char fmt2[] = " %4[0-9] %4[A-Z]";
if (sscanf(buffer1, fmt1, number, letters) != 2)
printf("sscanf() 1 failed\n");
else
printResult(fmt1, buffer1, number, "250", letters, "MEL");
if (sscanf(buffer2, fmt2, number, letters) != 2)
printf("sscanf() 2 failed\n");
else
printResult(fmt2, buffer2, number, "250", letters, "MEL");
number[0] = '\0';
letters[0] = '\0';
if (sscanf(buffer2, fmt1, number, letters) != 2)
printf("sscanf() 3 failed\n");
else
printResult(fmt2, buffer1, number, "250", letters, "MEL");
const char fmt3[] = "%4[0-9]s%c";
const char fmt4[] = "%4[0-9]%c";
char buffer3[] = "9876sun";
char buffer4[] = "9876moon";
char letter;
if (sscanf(buffer3, fmt3, number, &letter) != 2)
printf("sscanf() 4 failed\n");
else
printf("Data [%s], Format [%s], Output [%s] %c\n", buffer3, fmt3, number, letter);
if (sscanf(buffer3, fmt4, number, &letter) != 2)
printf("sscanf() 5 failed\n");
else
printf("Data [%s], Format [%s], Output [%s] %c\n", buffer3, fmt4, number, letter);
if (sscanf(buffer4, fmt3, number, &letter) != 2)
printf("sscanf() 6 failed\n");
else
printf("Data [%s], Format [%s], Output [%s] %c\n", buffer4, fmt3, number, letter);
return 0;
}
static int strings_match(const char *actual, const char *expected)
{
int rc;
if (strcmp(actual, expected) == 0)
{
rc = 1;
printf(" Output: [%s]", actual);
}
else
{
rc = 0;
printf(" Expected Output: [%s], Actual Output: [%s]", expected, actual);
}
return rc;
}
static int testcount = 1;
static void printResult(const char *format, const char *data, const char *act1,
char *exp1, const char *act2, char *exp2)
{
printf("Format: %d. [%s] Data: [%s]", testcount++, format, data);
int t1 = strings_match(act1, exp1);
int t2 = strings_match(act2, exp2);
if (t1 == 1 && t2 == 1)
printf(" - SUCCESS\n");
else
printf(" - FAILED\n");
}
Output:
Format: 1. [%4[0-9]%4[A-Z]] Data: [250MEL#93] Output: [250] Output: [MEL] - SUCCESS
Format: 2. [ %4[0-9] %4[A-Z]] Data: [ 250 MELabc] Output: [250] Output: [MEL] - SUCCESS
sscanf() 3 failed
Data [9876sun], Format [%4[0-9]s%c], Output [9876] u
Data [9876sun], Format [%4[0-9]%c], Output [9876] s
sscanf() 6 failed
Note how the last two successful conversion lines differ — the s in the format string is matched as a literal to the data, leaving u to be read into the character, compared with when there is no s in the format string and the character matches the s. In contrast, when the format looks for an s and finds m, the overall sscanf() fails — it only manages 1 instead of 2 conversion specifications.

How to make a C program that can read a data and copy some in a variable?

I'm a student, I am wondering...
How can I make a program that can Get some data from my text file to a variable on my program and print them
Example:
My Text File
I,Ate,Cookies
She,Drink,Coffee
Tom,Wears,Pyjamas
My code
main()
{
FILE *fp=fileopen("c:\\textfile.txt","r");
char name[20],action[20],item[20];
prinf("Enter name: \n");
scanf("%s",&name);
/* I dont Know what to do next */
}
I though about some checking code:
if (name==nametxt) /*nametxt is the first line on the text file */
{
printf("%s\n %s\n %s\n",name,action,item);
}
If the name is "I",the output would look like this :
Enter name:
I
I
Eat
Cookies
A help will satisfy my curiosity thanks in advance
You are reading characters from file until you receive new line character (\n) or fill an array, then you return characters stored in an array passed by caller.
From this returned array you may get separated values with strtok.
Repeat until you receive 0 from getline (Getline received EOF from file.)
Here is simple example with your own getline function which you may modify.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int getline(char s[],int lim, FILE * fp)
{
int c, i;
for (i=0; i < lim-1 && (c=fgetc(fp))!=EOF && c!='\n'; ++i)
{
s[i] = c;
}
if (c == '\n')
{
s[i] = c;
++i;
}
s[i] = '\0';
return i;
}
int main()
{
FILE * fp = fopen("c:\\textfile.txt", "r");
char line[100];
char * ptr;
while (getline(line, 100, fp))
{
ptr = strtok(line, ",");
while( ptr != NULL )
{
printf(" %s\n", ptr);
ptr = strtok(NULL, ",");
}
}
return 0;
}
Output
I
Ate
Cookies
She
Drink
Coffee
Tom
Wears
Pyjamas
Storing strings into variable isnt tough, here is an example
strcpy(name, ptr);
But be careful, writing outside of bounds have undefined behavior.
strncpy(name, ptr, 100); You can limit number of copied characters with strncpy, but be careful, this function is error-prone.
You can do like this,
Go on reading characters from a file, after every character is read compare with ',' character.
If the character read is ',' then you have finished reading the name, otherwise store it in a character array and continue reading the file.
Once you hit ',' character, terminate the character array with null character(Now you have a complete name with you).
Compare this character array with a string you receive as input using a strcmp(String compare function). If its it matches decide what you wanna do?
I hope i am clear.
There is different ways to read data from a FILE * in C :
You read only one character : int fgetc(FILE *fp);.
You read a whole line : char *fgets(char *buf, int n, FILE *fp); (take care to buf, it must point to allocate memory).
You read a formatted string, which is your case here : int fscanf(FILE *stream, const char *format, ...), it works like printf() :
This way :
char name[20], action[20], item[20];
FILE *f = fopen("myfile.txt", "r");
if (! f)
return;
if (3 == fscanf(f, "%19[^,\n],%19[^,\n],%19[^,\n]\n", name, action, item))
printf("%s %s %s\n", name, action, item)
%30[^,\n], here is used to read of whole object of your line, except , or \n, which will read item by item the content of your string.
start with like this
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define DATA_FILE "data.txt"
#define LEN 19
#define SIZE (LEN+1)
//Stringification
#define S_(n) #n
#define S(n) S_(n)
enum { NOT_FOUND, FIND };
int pull_data(const char name[SIZE], char action[SIZE], char item[SIZE]){
int ret = NOT_FOUND;
FILE *fp = fopen(DATA_FILE, "r");//fileopen --> fopen
if(fp == NULL){
perror("fopen:");
exit(EXIT_FAILURE);
} else {
char nametxt[SIZE];
*action = *item = 0;
while(fscanf(fp, "%" S(LEN) "[^,],%" S(LEN) "[^,],%" S(LEN) "[^\n]%*c", //"%19[^,],%19[^,],%19[^\n]%*c"
nametxt, action, item) == 3){
if(strcmp(name, nametxt) == 0){//Use strcmp for comparison of strings
ret = FIND;
break;
}
}
}
fclose(fp);
return ret;
}
int main(void){
char name[SIZE], action[SIZE], item[SIZE];
printf("Enter name: \n");//prinf --> printf
if(scanf("%" S(LEN) "s", name) == 1){
if(pull_data(name, action, item) == FIND){
printf("%s\n%s\n%s\n", name, action, item);
} else {
printf("%s not found.\n", name);
}
}
}

Parsing house number from street address represented as a char[]

Suppose I have a street address stored as a char[]. Examples of valid values:
1600 Pennsylvania Ave
1 Infinite Loop
221 Baker Street
As you can see, the house number can be of any length.
In C, what is an efficient way of separating the house number into its own int? I'm thinking I need to write a while loop to check for each char c if isdigit(c), but I don't know if I'm on the right track here in terms of implementation.
You can use strtok to break up the string into tokens and use isdigit() to figure out if that token is numeric.
#include <string.h>
#include <stdio.h>
int main()
{
const char str1[80] = "1600 Pennsylvania Ave";
int houseNumber = 0;
const char s[2] = " ";
char *token;
/* get the first token */
token = strtok(str, s);
/* walk through other tokens */
while( token != NULL ) {
printf( " %s\n", token );
if (isdigit(str1[0])) {
houseNumber = atoi (token);
}
token = strtok(NULL, s);
}
return(0);
}
Alternatively, you can use sscanf to read the entire string and automatically parse everything:
#include <string.h>
#include <stdio.h>
int main()
{
const char str1[80] = "1600 Pennsylvania Ave";
int houseNumber = 0;
char streetName[50];
char streetExt[20];
sscanf (str1,"%d %s %s", &houseNumber, streetName, streetExt);
return(0);
}
This last method depends on the format of the strings being exactly the same in all cases, meaning that it's always a number followed by 2 strings. The strtok method will be a little more fault tolerant if there's more other stuff.
Consider the following solution:
#include <stdio.h>
#include <string.h>
int main(void)
{
char address[255];
char * ptr;
int number;
char strnumber[100];
char strstreet[255];
// ask adress
printf("Please, enter the addres: ");
// put end of string replacing newline
fgets(address, 255, stdin);
ptr = strchr(address, '\n');
if(ptr)
{
*ptr = '\0';
}
else
{
address[254] = '\0';
}
// try to read whole number from the beggining of the string
if( 1 == sscanf(address, "%d", &number) )
{
// make number as a string (if it is needed)
sprintf(strnumber, "%d", number);
// take streat to separate string
ptr = strchr(address + strlen(strnumber), ' '); // find the firs space
if( ptr )
{
strcpy(strstreet, ptr + 1); // +1 just to skip the found space
}
}
else
{ // if no number at the beginning of address string
number = 0;
strnumber[0] = '\0';
strstreet[0] = '\0';
}
// show the results
printf("You have entered a string:\n%s\n", address);
printf("The found number is:\n%d\n", number);
printf("The found number as a string:\n%s\n", strnumber);
printf("The address without number is:\n%s\n", strstreet);
}
I would use strstr and atoi like this
char someAddress[80] = "1600 Pennsylvania Ave";
char* p = strstr(someAddress, " ");
if (p)
{
*p = 0; // Terminate string, i.e. cheat for a moment
int number = atoi(someAddress);
*p = " "; // Restore someAddress
}
else
{
// Handle illegal format in someAddress
}
This method shall only be used when you know it is safe to modify someAddress for a short period.
This is one situation with the numbers first, where it is much easier just to use a simple pointer and an if statement to parse the line:
#include <stdio.h>
#define ADDL 64
int main (void) {
char address[ADDL] = {0};
char street[16] = {0};
while (fgets (address, ADDL-1, stdin) != NULL)
{
char *ap = address;
char *sp = street;
while (*ap >= '0' && *ap <= '9') /* while the char is a number */
{
*sp = *ap++; /* copy to street number */
sp++;
}
*sp = 0; /* null-terminate */
printf (" Address: %s Number : %s\n\n", address, street);
}
return 0;
}
Output
$ ./bin/split_address < dat/houses.txt
Address: 1600 Pennsylvania Ave
Number : 1600
Address: 1 Infinite Loop
Number : 1
Address: 221 Baker Street
Number : 221
Note: the printf statement above makes use to the embedded newline at the end of address rather than stripping it as you would normally do. Also note that if you want the number as an integer, long, or unsigned, simply call atoi, strtol or strtoul on street.

Detecting single character in string

So, I'm trying to detect a single character in a string. There must be no other characters besides whitespace and a null character. This is my first issue, as my code detects the character in a string with other characters (besides the whitespace).
My second issue, is I can't seem to figure out how best to read matrices from a file. I'm supposed to read the first line and get the ROWS x COLUMNS. Then I'm supposed to read the data into the a matrix array that is stored globally. Then reading the second matrix into a second matrix array (stored globally as well).
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <string.h>
#define MAXLINE 100
typedef struct matrixStruct{
int rows;
int columns;
}matrixStruct;
typedef int bool;
enum{
false,
true
};
/*
*
*/
int aMatrix1[10][10];
int aMatrix2[10][10];
int multiMatrix[10][10];
int main(int argc, char** argv){
FILE *inputFile;
char tempLine[MAXLINE], *tempChar, *tempString;
char *endChar;
endChar = (char *)malloc(sizeof(char));
(*endChar) = '*';
bool readFile = true;
inputFile = fopen(argv[1], "r");
if(inputFile == NULL){
printf("File %s not found.\n", argv[1]);
perror("Error");
exit(EXIT_FAILURE);
}else{
printf("File opened!\n");
}
int numRow, numColumn, i, j, tempNum, count = 0;
do{
fgets(tempLine, MAXLINE, inputFile);
tempChar = strchr(tempLine, '*');
if(tempChar != NULL){
printf("True # %s\ncount=%d\n",tempChar,count);
readFile = false;
}else{
sscanf(tempLine, "%d %d", &numRow, &numColumn);
count++;
for(i=0;i<numRow;i++){
fgets(tempLine, MAXLINE, inputFile);
for(j=0;j<numColumn;j++){
aMatrix1[i][j] = atoi(tempNum);
}
}
}
}
while(readFile);
printf("aMatrix1[%d][%d]= \n", numRow, numColumn);
for(i=0; i < numRow;i++){
for(j=0; j < numColumn; j++){
printf("aMatrix[%d][%d] = %d\t", i, j, aMatrix1[i][j]);
}
printf("\n");
}
return (EXIT_SUCCESS);
}
For the first issue you could do what you suggested in your comment (regexp are an overkill here) - loop through the string, break on any non-whitespace char that's not what you expect, and count the ones that do match - you don't want 0 matches, and i guess also no more than 1.
However, I suggest you read the man page for strtok - I normally wouldn't suggest it as it's not thread-safe and has strange behaviors, but in this simple case it could work fine - provide whitespace chars as delimiters, and it would return the first non-whitespace string. If that's doesn't strcmp with "*", or if the next call to strtok doesn't return null, then it's not a match.
By the way - what do you plan to do with lines that aren't " .. * .. " or " ROWS x COLUMNS "? you're not handling them right now.
As for the second issue - strtok again could come to the rescue - repeated calls would just give you the whitespace-delimited numbers (as strings), and you'll be able to populate tempNum for each iteration.

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