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sscanf skipping the final value when reading multiple values from a line


sscanf skipping the final value when reading multiple values from a line

By : userG
Date : October 20 2020, 06:10 AM
around this issue %[^|]s always fails because %[^|] consumes all non-pipe characters including s, so s then never matches.
That is, %[^|] is a scanf input directive, but s in the format string just matches itself. Just remove that s.
code :
if (sscanf(buffer, "%d | %d | %d | %[^|] | %[^|] |",
                   &dump, &sa[i].v1, &sa[i].v2, sa[i].v3, sa[i].v4) != 5) {
    /* handle input error somehow */
}


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Sscanf problem and reading from command-line

Sscanf problem and reading from command-line


By : Devaiah Chendanda
Date : March 29 2020, 07:55 AM
will be helpful for those in need Hello hahah yet again. C- Unix Im reading something like this: , It works for me
code :
#include <stdio.h>
int main(int argc, char **argv) {
    int a, b;
    char operand1;
    int n;

    printf("scanning argv[argc - 1]: %s\n", argv[argc - 1]);
    /* It works for me */
    n = sscanf(argv[argc - 1], "[%d%c%di]", &a, &operand1, &b);

    printf("%d values read\n", n);
    if (n != 3) printf("there was an error in scanf ...\n");
    printf("The values were %d, %c, and %d\n", a, operand1, b);
    return 0;
}
$ ./a.out [23+43i]
scanning argv[argc - 1]: [23+43i]
3 values read
The values were 23, +, and 43
Reading in a multi-line string from a file using sscanf in C

Reading in a multi-line string from a file using sscanf in C


By : silvano Albuquerque
Date : March 29 2020, 07:55 AM
help you fix your problem I've got a text file that has information about a specific record, and the format of the file looks like this:
code :
#include <stdio.h>
#include <string.h>

#define MAX_RECORDS 64

typedef struct {
    char    title[80];
    char    artist[80];
    int     year;
    char    genre[80];
    char    label[80];
    double  price;
} Record;

Record record_inventory[MAX_RECORDS];

int main(void){
    char input[128], rec[6*128] = "";
    int n = 0;
    FILE *ifp = fopen("data.txt", "r");


    while(fgets(input, sizeof input, ifp)){
        if(strncmp(input, "----", 4)==0){
            if(6!=sscanf(rec ,
                "Title: %79[^\n] "
                "Artist: %79[^\n] "
                "Year: %d "
                "Genre: %79[^\n] "
                "Label: %79[^\n] "
                "Price: %lf",
                record_inventory[n].title,
                record_inventory[n].artist,
                &record_inventory[n].year,
                record_inventory[n].genre,
                record_inventory[n].label,
                &record_inventory[n].price)){
                fprintf(stderr, "bad format!\n");
            } else {
                if(++n == MAX_RECORDS){
                    fprintf(stderr, "full.\n");
                    break;
                }
            }
            *rec = '\0';
        } else {
            strcat(rec, input);//strcat up to ----
        }
    }
    fclose(ifp);
    //check print
    for(int i = 0; i < n; ++i){
        printf("%s : %f\n", record_inventory[i].title, record_inventory[i].price);
    }
    return 0;
}
Reading line per line, and evaluating strings into coordinates using fgets() and sscanf()

Reading line per line, and evaluating strings into coordinates using fgets() and sscanf()


By : Tom Hue
Date : March 29 2020, 07:55 AM
seems to work fine I'm trying to read multiple lines of vertices with varying length using fgets and sscanf. , It's because this
code :
while(sscanf(temp3, "(%d,%d)", 
  &polygonx[polycount][vertcount], &polygony[polycount][vertcount]) != EOF)
 {
 }
while(sscanf(temp3, "(%d,%d)", 
  &polygonx[polycount][vertcount], &polygony[polycount][vertcount]) == 2)
 {
 }
next = strchr(temp3, ',');
if (next != NULL)
    temp3 = next + 1;
else
    /* you've reached the end here */
#include <stdio.h>
#include <string.h>

int
main(void)
{
    const char temp3[] = "(1,6),(2,6),(2,9),(1,9)\n(1,5)";
    char *source;
    int x, y;
    int count;
    source = temp3;
    while (sscanf(source, "(%d,%d)%*[^(]%n", &x, &y, &count) == 2)
    {
        /* this is just for code clarity */
        polygonx[polycount][vertcount] = x;
        polygony[polycount][vertcount] = y;
        /* Process here if needed, and then advance the pointer */
        source += count;
    }
    return 0;
}
Reading multiple values from formatted string using sscanf

Reading multiple values from formatted string using sscanf


By : Lawrence Lanzaderas
Date : March 29 2020, 07:55 AM
I wish did fix the issue. I'm trying to extract two values from a string. The first is an 8 digit hexadecimal value, and the second is an unsigned 1-4 digit value. The values should also be preceded by a command which tells the program what to do with the values, in this case "read". Some examples of the format: ,
What am I doing wrong?
code :
Input:  "read 0x1234ABCD 2000"
Format: "read 0x%x[0-9a-fA-F]{8} %u[0-9]{1,4}"
const char *f1 = "read 0x%x %u";
const char *f2 = "read 0x%x%u";   // Space not need, yet looks good
const char *f3 = "read %x%u";     // Always read addr as hex, even with/without 0x
const char *f4 = "read %x %u";
const char *f5 = "read%x%u";

unsigned addr;
unsigned len;
int n = sscanf(str, fn, &addr, &len);  // select format from above
"read 0x0x123 +1234"
"read 0x123 456 xyz"
"read 0x123 12345"
"read 0x+123 -123"
unsigned addr;
unsigned len;
char sentinel;
int n = sscanf(str, "read 0x%8x %4u %c", &addr, &len, &sentinel);
if (n != 2){
  // Wrong format...
}
"read 0x123 456 xyz"
#define F_RD    "read"
#define F_SP    "%*[ ]"
#define F_ADDR  "0x%8[0-9a-fA-F]"
#define F_LEN   "%4[0-9]"
#define F_SEN   " %c"
char addr_s[8+1];
char len_s[4+1];
char sentinel;
int n = sscanf(str, F_RD F_SP F_ADDR F_SP F_LEN F_SEN, addr_s, len_s, &sentinel);
if (n == 2){
  // Success
  unsigned long addr = strtoul(addr_s, (char **)NULL, 16);
  unsigned len = strtoul(len_s, (char **)NULL, 10);
  ...
}
Loop skipping first line of text file being read, working for second line, but also not reading third line

Loop skipping first line of text file being read, working for second line, but also not reading third line


By : Vamshidhar Madas
Date : March 29 2020, 07:55 AM
may help you . In your while loop, you do two reads. The first is read -r line reads the first line then read CENTRIFY_USER which is the second line. You do not appear to be using $line in you script.
You appear to need:
code :
while IFS='' read -r CENTRIFY_USER; do

    export CENTRIFY_USER

    .... 

    done < centrify_users_to_add.txt
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