FAQ Database Discussion Community


Why do these two methods of counting words differ significantly?

c,regex,text,fscanf,text-parsing
I wrote a program that allows a user to find the number of instances of a word or collection of words in any text file. The user can enter something like this in the command line: $ ./wordCount Mars TripToMars.txt to search for the number of instances of the word...

C Programming: Error in program. Won't show Max/Min/Average of files inputted by user

c,file-io,fscanf
I'm attempting to create a code that the user inputs a filename and the program will then find the Min, Max, and Average of the numbers in the file. This is a sample of a file the user would input into the program (the # are comments and would be...

Ignoring return value of fscanf and Segmentation fault

c,segmentation-fault,fopen,compiler-warnings,fscanf
I was wondering how to solve a Core dumped issue on my C code. When I compile it with: g++ -g MatSim.cpp -o MatSim -lstdc++ -O3, I get three warnings, this is one (The other two are similar and are only differentiated by the string variable name): MatSim.cpp: In function...

fscanf line with condition

c++,fgets,fscanf
my goal is to read in a data file consisting of just one number per line and write the data into a histogram. There are some comments in the file behind # characters. I want to skip these lines. I have started writing: TH1F *hist = new TH1F("hist","",4096, -0.5,4095.5); //TF1...

c fscanf changes string variable?

c,variables,while-loop,fscanf
i'm a beginner in programming and i'm currently learning c. (through harvard edx cs50). But i've come across something that confuses me. So in my while loop i have: char* bword = word fscanf(fp, "%s", word); Where word is a char[46], bword is a char* and fp is the file...

return permanent pointer to array after saving delimited text file to it

c,arrays,fscanf
i am trying to store a text file looking like this: Headphones-750, TV-1500, Keyboard-1200, Tablet-80, Speakers-400, DVD-250, Streamer-550, Mouse-50; into an array of type def: typedef struct item{ char* name; int price; }item; typedef struct item{ char* name; int product_code; int price; }item; item *getProducts(){ FILE *fp; fp = fopen("machinedata.txt",...

Fscanf, Strings, and Arrays in C? [closed]

c,arrays,string,fscanf
I have a programming assignment. The code is laid out for us, we just have to fill it in. Its been a while since i've touched arrays so i need some help. The program is declaring a char array. It is using fscanf to get strings from a file. The...

Find out if you're reading int or double using fscanf

c,parsing,int,double,fscanf
I have a text file that I want to read using C. It contains lines in this format: %d %d (%d or %lf). An example of 3 lines: 1 0 44 2 0 84.13 3 1 15.07 But the last number can be either int or double, arbitrary. How can...

Trouble using fscanf to read coordinates in C

c,segmentation-fault,coordinates,fscanf
I know similar questions have been asked but none of them seemed to solve my problem. I get Segmentation fault (core dumped) when I run my code. The first line in "data.dat" has the total number of points in the file and the next lines have the point coordinates (in...

Best way to store the first and second word of a text file into two arrays

c,arrays,char,fopen,fscanf
I'm making a code for a program. It would have three text files: -list1.txt having a column of words like: Cat Dog Fish Computers -change.txt having two columns of text like Dog Marbles Computers Store -list2.txt being empty The program would take list.txt, and store its words in the list2.txt,...

C sscanf (fscanf) behaving differently row from row

c,scanf,fscanf,sscanf
I've this snippet of code which should read text from input file and put it in a struct. void load(FILE *fin, struct camion payload[]){ int i=0; char except; char buf[1000]; while (fgets(buf,sizeof(buf),fin)){ except='A'; sscanf(buf,"%i-%i-%i %i %s %c",&payload[i].day,&payload[i]. month,&payload[i].year,&payload[i].nparcels,payload[i].origin,&except); if (except=='E') payload[i].except=1; i++; } } The fgets works as it should...

Variable is printed properly right before an if else loop, but does not retain that value one in the if else loop

c,if-statement,fscanf
I've written a program that reads an account value from a text file and then assigns these values to a variable for each account. Once this is done, reading from the same text file, an action to be done to each account value is identified in the format "Account# Actiontype...

How to properly use fscanf to store only the needed information in an array?

c,arrays,file,fscanf
I'm trying to write a program in c that reads a mtx file (mtx stands for midi to text, it's actually a txt file) and stores only the information I need (specifically only the note-on/off and pitch-bend messages) here's an example: the information that I need are: the timing (first...

Read File: fscanf doesn't read whitespaces?

c,fscanf
I have a problem fetching lines from File Pointer using fscanf. Let's say a want to fetch a line like this: <123324><sport><DESCfddR><spor ds> Fscanf fetch only this part: <123324><sport><DESCfddR><spor Does anybody know how to overcome this problem? Thanks in advance....

what does fscanf being == 1 do

c,file,input,fscanf
Hey guys there is more to this code obviously but I am just curious as to what this line of code actually does. I know the while loop and such but am new to the fscanf() while (fscanf(input_file, "%s", curr_word) == 1) ...

C fscanf to read between square brackets

c,file,fscanf,brackets,square
I have a file which includes datas as [name surname] [birthday] [id] when i try this code while(fscanf(file,"%s %s %s",name,bdate,uid) == 3) bdate gets surname] as a value how can i read informations between square brackets. thanks....

Problems with taking input from stdin - Invalid read/write from valgrind

c,io,stdin,fgets,fscanf
I ran valgrind on a program I'm working on and I'm getting the following errors - I can't figure out why. Any help would be greatly appreciated ahead of time. Let me know if you need any more information ==27928== Invalid read of size 1 ==27928== at 0x4EB9390: __GI___rawmemchr (rawmemchr.S:25)...

While loop through text file stops unexpectedly

c,file,while-loop,integer,fscanf
I am trying to loop through a text file that contains random content. It's current contents are: "13 -35 57 - 23723724 12taste-34the+56rain-bow845" My program should only get the numbers from the file (-35 as a negative number, but not - 23723724 due to the space in between) and no...

fscanf() reading string with spaces in formatted lines

c,fscanf
Using this structure: typedef struct sProduct{ int code; char description[40]; int price; }; I want to read a txt file with this format: 1,Vino Malbec,12 where the format is: code,description,price. But I'm having problems to read the description when it has a space. I tried this: fscanf(file,"%d,%[^\n],%d\n",&p.code,&p.description,&p.price); The code is...

Invalid read of size 4 on fscanf

c,arrays,valgrind,dynamic-arrays,fscanf
Running my program through valgrind, I'm getting an invalid read of size 4 error in the following code (I think at the line where fscanf is called) Important Info: numIntegers is the maximum number of integers that can be read, while numsInFile specifies the amount of integers present in the...

reading from a text file using fscanf()

c,arrays,struct,fscanf
I'm having trouble figuring out what went wrong in my code. I think that my while loop didn't read the file correctly, I was trying to print out the customer name but nothing shows up. for example, I have a file like this. Smith 3 Sweater $22.50 Reich 3 Umbrella...

Unclear error in list implementation

c,linked-list,fscanf
I wrote a function to get input from text files, the "fileInput" function, and the content of my text file is like 1 2 4 5 2 4 5 6 the part of main function is like: case 7 head=fileInput(head);break; but for some reason, when I choose case 7 to...

Converting binary serialization to human-readable serialization

c,printf,fopen,fread,fscanf
I'm converting a program that used to do a binary dump of a struct to file and read that binary struct back in using fread. I want to convert it to creating and reading human readable data files, which of course means I need to format the data and such....

Do white spaces take space in txt files?

c,file-io,whitespace,scanf,fscanf
I'm wondering if the white spaces take space in txt files for C. For example if i'm going to take the file pointer back using fseek() or if I am going to fscanf an input from a file do I need to consider white spaces? A Assume a file has...

How to fscanf from a .csv which is a output of fprintf

c,printf,fscanf
I want to fscanf a csv file which is a output of fprintf, I set the same format but it didn't work, which means when I use that function to fscanf the file I just made, it didn't succuss, even didn't get into the while-loop. So, how to modify it...

C programming - reading numbers from text file

c,fscanf
I'm trying to make a sort of a database program and ran into a few issues with reading integers from a text file in C. I have the following code: #include <stdio.h> int main(){ int index; FILE * fp; if((fp = fopen("read_file.txt","r+")) == NULL){ perror("Cannot open file"); printf("\nCreating new file...");...

C/C++ How to convert back int to string (a word)?

c,string,int,fscanf
In C I'm reading a string from a txt file, for example the string "hello", so i have my: F=fopen("text.txt","r"); fscanf(F,"%s\n",string); Now, if i want to convert this string to hex and decimal, i can do something like this: for (i=0; i<strlen(string); i++) { sprintf(st, "%02X", string[i]); //Convert to hex...

Read data only when it is present

matlab,data,serial-port,fscanf
I try to read data from the COM3 port. I'm using : in = fscanf(s); if(in == 'A') fclose(s); break; end The problem is, when no data is send to the com3 port, the fscanf line will wait for a certain time and than give a timeout. Is there a...

how to handle `%` if it is present in a string while reading it using `fscanf()`

c,fscanf
Let's say there is a file a.txt in which each string is a key values pair as <key: value>. But one constraint is that my key could contains character like % too. For example: as given below string : INDIA integer : 2015 ratio %: 20 integer2 : 2016 Now...