Timeline for Emulating C++ string input in C
Current License: CC BY-SA 4.0
22 events
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| Jun 10, 2020 at 13:24 | history | edited | Community Bot |
Commonmark migration
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| Jun 27, 2018 at 5:21 | comment | added | jamesqf | @Toby Speight: It may be a "standard" idiom, at least among those who like to obfuscate their code, but that does not make it any less a source of potential confusion. | |
| Jun 26, 2018 at 16:22 | comment | added | Sandro4912 |
Also in the String_read method you dont initalize ch. I know it gets initalized directly in the next statement while (ch = getc(stdin) != EOF && !isspace(ch)) . However on my compiler (visual studio 2017) it terminates the programm with "Run-Time Check Failure #3 - The variable 'ch' is being used without being initialized."
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| Jun 26, 2018 at 16:18 | comment | added | Sandro4912 |
my other question is return 0; in main also optional in c? I thought it only gets compiler generated in c++
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| Jun 26, 2018 at 16:16 | comment | added | Sandro4912 |
the corrected code gives errors shouldnt void String_print(struct String *restrict string, FILE *restrict stream) be void String_print(struct String *restrict_string, FILE *restrict_stream)? why the restrict?
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| Jun 26, 2018 at 12:26 | comment | added | Toby Speight |
Thanks @chux (for the link correction (I accidentally deleted the /a - oops) and for the comment that's much clearer and more accurate than what I said - yes, it's the conversion from int that matters, not the literal 0).
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| Jun 26, 2018 at 11:43 | comment | added | chux | 3rd link [here] is broken. Should be this | |
| Jun 26, 2018 at 11:41 | comment | added | chux |
Detail: "0 always means a null pointer" is amiss. 0 is always a constant int with value 0. Comparing that int to a pointer p, converts the int 0 to a null pointer. IAC, if (!tmp) is OK, yet as a minor point, I prefer if (tmp == NULL) as negations tend to be less clear than positive assertions - don't you not think is won't be otherwise ;-)? (Good review)
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| Jun 26, 2018 at 7:42 | comment | added | Toby Speight |
Further reading: see the answers to Does Standard define null pointer constant to have all bits set to zero?, Why is address zero used for the null pointer? and Can I use if (pointer) instead of if (pointer != NULL)?.
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| Jun 26, 2018 at 7:35 | comment | added | Toby Speight |
@james/hoffmale: It's a standard C (and C++) idiom to test the validity of a pointer by leaving the comparison to 0 implicit. Remember that a literal 0 always means a null pointer (whether or not the machine uses all-bits-zero for its representation). NULL doesn't "just happen" to be implemented as 0 - the Standard insists that it must be 0, even on hardware where the zero address is valid. In those cases, the implementation is required to evaluate a pointer holding the zero address as a "true" value.
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| Jun 26, 2018 at 7:30 | comment | added | Toby Speight |
@sandro: Positive numbers are the standard convention for exit codes; most shells will truncate/convert to unsigned values - to demonstrate, you can ( exit -1 ); echo $? in Bash. So, small positive numbers ensure consistency between what you say you're returning and what your users see.
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| Jun 26, 2018 at 3:13 | comment | added | hoffmale |
@jamesqf: That should be "happen to be implemented as 0 in your C implementation". In some implementations (e.g. embedded), 0 is actually a completely valid address.
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| Jun 25, 2018 at 20:33 | comment | added | jamesqf | One nit to pick. I would change "if (!tmp)" to "if (tmp == NULL)", because tmp is not a logical (true/false) condition, it's a comparison to a special value, the NULL pointer. FALSE and NULL just happen to be implemented as 0 in C, but that's not necessarily universally true. | |
| Jun 25, 2018 at 18:35 | vote | accept | Sandro4912 | ||
| Jun 25, 2018 at 18:34 | comment | added | Sandro4912 |
thanks for the in deep review. i have to admit i didn't even expected to read much comments to this code because i considered the code to easy and short :-) I was quite wrong... One question i have hwat would be an better error handling? and why exit(1) not exit(-1)
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| Jun 25, 2018 at 17:46 | history | edited | Toby Speight | CC BY-SA 4.0 |
Suggest a bigger initial size to save on mem usage (stolen from hoffmale's deleted answer)
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| S Jun 25, 2018 at 17:41 | history | suggested | Andrew | CC BY-SA 4.0 |
added missing struct reference
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| Jun 25, 2018 at 17:37 | review | Suggested edits | |||
| S Jun 25, 2018 at 17:41 | |||||
| Jun 25, 2018 at 17:01 | history | edited | Toby Speight | CC BY-SA 4.0 |
Add a lesson on invariants; various fixes
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| Jun 25, 2018 at 16:55 | history | edited | Toby Speight | CC BY-SA 4.0 |
Finish the review
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| Jun 25, 2018 at 16:36 | history | edited | Toby Speight | CC BY-SA 4.0 |
Add String_init
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| Jun 25, 2018 at 16:25 | history | answered | Toby Speight | CC BY-SA 4.0 |