Using printf with a non-null terminated string
There is a possibility with printf, it goes like this: printf(“%.*s”, stringLength, pointerToString); No need to copy anything, no need to modify the original string or buffer.
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Using colors with printf
Rather than using archaic terminal codes, may I suggest the following alternative. Not only does it provide more readable code, but it also allows you to keep the color information separate from the format specifiers just as you originally intended. blue=$(tput setaf 4) normal=$(tput sgr0) printf “%40s\n” “${blue}This text is blue${normal}” See my answer HERE … Read more
How does the below program output `C89` when compiled in C89 mode and `C99` when compiled in C99 mode?
C99 allows //-style comments, C89 does not. So, to translate: C99: printf(“C%d\n”,(int)(90-(-4.5 /*Some comment stuff*/ -4.5))); // Outputs: 99 C89: printf(“C%d\n”,(int)(90-(-4.5/ -4.5))); /* so we get 90-1 or 89 */
Avoid trailing zeroes in printf()
This can’t be done with the normal printf format specifiers. The closest you could get would be: printf(“%.6g”, 359.013); // 359.013 printf(“%.6g”, 359.01); // 359.01 but the “.6” is the total numeric width so printf(“%.6g”, 3.01357); // 3.01357 breaks it. What you can do is to sprintf(“%.20g”) the number to a string buffer then manipulate … Read more
What’s up with Java’s “%n” in printf?
From a quick google: There is also one specifier that doesn’t correspond to an argument. It is “%n” which outputs a line break. A “\n” can also be used in some cases, but since “%n” always outputs the correct platform-specific line separator, it is portable across platforms whereas”\n” is not. Please refer https://docs.oracle.com/javase/tutorial/java/data/numberformat.html Original source
What is the conversion specifier for printf that formats a long?
Put an l (lowercased letter L) directly before the specifier. unsigned long n; long m; printf(“%lu %ld”, n, m);
Left-pad printf with spaces
If you want the word “Hello” to print in a column that’s 40 characters wide, with spaces padding the left, use the following. char *ptr = “Hello”; printf(“%40s\n”, ptr); That will give you 35 spaces, then the word “Hello”. This is how you format stuff when you know how wide you want the column, but … Read more
Printf width specifier to maintain precision of floating-point value
I recommend @Jens Gustedt hexadecimal solution: use %a. OP wants “print with maximum precision (or at least to the most significant decimal)”. A simple example would be to print one seventh as in: #include <float.h> int Digs = DECIMAL_DIG; double OneSeventh = 1.0/7.0; printf(“%.*e\n”, Digs, OneSeventh); // 1.428571428571428492127e-01 But let’s dig deeper … Mathematically, the … Read more
What is the use of the %n format specifier in C?
Most of these answers explain what %n does (which is to print nothing and to write the number of characters printed thus far to an int variable), but so far no one has really given an example of what use it has. Here is one: int n; printf(“%s: %nFoo\n”, “hello”, &n); printf(“%*sBar\n”, n, “”); will … Read more
Java: Literal percent sign in printf statement
The percent sign is escaped using a percent sign: System.out.printf(“%s\t%s\t%1.2f%%\t%1.2f%%\n”,ID,pattern,support,confidence); The complete syntax can be accessed in java docs. This particular information is in the section Conversions of the first link. The reason the compiler is generating an error is that only a limited amount of characters may follow a backslash. % is not a … Read more