C - Split string with repeated delimiter char into 2 substrings
I'm making a very simple C program that simulates the export command, getting an input with fgets().
Input example:
KEY=VALUE
Has to be converted to:
setenv("KEY", "VALUE", 1);
That's easy to solve with something similar to this code:
key = strtok(aux, "=");
value = strtok(NULL, "=");
The problem comes when the user input a value that start with one or several equals = characters. For example:
KEY===VALUE
This should be converted to:
setenv("KEY", "==VALUE", 1);
But with my current code it is converted to:
setenv("KEY", NULL, 1);
How I can solve this?
Thanks in advice.
c strtok
asked Nov 13 '18 at 19:05
Tony CeralvaTony Ceralva
7471720
add a comment |
I'm making a very simple C program that simulates the export command, getting an input with fgets().
Input example:
KEY=VALUE
Has to be converted to:
setenv("KEY", "VALUE", 1);
That's easy to solve with something similar to this code:
key = strtok(aux, "=");
value = strtok(NULL, "=");
The problem comes when the user input a value that start with one or several equals = characters. For example:
KEY===VALUE
This should be converted to:
setenv("KEY", "==VALUE", 1);
But with my current code it is converted to:
setenv("KEY", NULL, 1);
How I can solve this?
Thanks in advice.
c strtok
asked Nov 13 '18 at 19:05
Tony CeralvaTony Ceralva
7471720
You have to write your own parser.
– john elemans
Nov 13 '18 at 19:11
4
You could just usestrchrinstead ofstrtok
– Andrew Sun
Nov 13 '18 at 19:11
Can't reproduce. coliru.stacked-crooked.com/a/913d3de1fdad058a
– SergeyA
Nov 13 '18 at 19:13
add a comment |
I'm making a very simple C program that simulates the export command, getting an input with fgets().
Input example:
KEY=VALUE
Has to be converted to:
setenv("KEY", "VALUE", 1);
That's easy to solve with something similar to this code:
key = strtok(aux, "=");
value = strtok(NULL, "=");
The problem comes when the user input a value that start with one or several equals = characters. For example:
KEY===VALUE
This should be converted to:
setenv("KEY", "==VALUE", 1);
But with my current code it is converted to:
setenv("KEY", NULL, 1);
How I can solve this?
Thanks in advice.
c strtok
asked Nov 13 '18 at 19:05
Tony CeralvaTony Ceralva
7471720
I'm making a very simple C program that simulates the export command, getting an input with fgets().
Input example:
KEY=VALUE
Has to be converted to:
setenv("KEY", "VALUE", 1);
That's easy to solve with something similar to this code:
key = strtok(aux, "=");
value = strtok(NULL, "=");
The problem comes when the user input a value that start with one or several equals = characters. For example:
KEY===VALUE
This should be converted to:
setenv("KEY", "==VALUE", 1);
But with my current code it is converted to:
setenv("KEY", NULL, 1);
How I can solve this?
Thanks in advice.
c strtok
c strtok
asked Nov 13 '18 at 19:05
Tony CeralvaTony Ceralva
7471720
asked Nov 13 '18 at 19:05
Tony CeralvaTony Ceralva
7471720
edited Nov 13 '18 at 19:07
Tony Ceralva
asked Nov 13 '18 at 19:05
Tony CeralvaTony Ceralva
7471720
asked Nov 13 '18 at 19:05
Tony CeralvaTony Ceralva
7471720
asked Nov 13 '18 at 19:05
Tony CeralvaTony Ceralva
7471720
7471720
You have to write your own parser.
– john elemans
Nov 13 '18 at 19:11
4
You could just usestrchrinstead ofstrtok
– Andrew Sun
Nov 13 '18 at 19:11
Can't reproduce. coliru.stacked-crooked.com/a/913d3de1fdad058a
– SergeyA
Nov 13 '18 at 19:13
add a comment |
You have to write your own parser.
– john elemans
Nov 13 '18 at 19:11
4
You could just usestrchrinstead ofstrtok
– Andrew Sun
Nov 13 '18 at 19:11
Can't reproduce. coliru.stacked-crooked.com/a/913d3de1fdad058a
– SergeyA
Nov 13 '18 at 19:13
You have to write your own parser.
– john elemans
Nov 13 '18 at 19:11
You have to write your own parser.
– john elemans
Nov 13 '18 at 19:11
4
4
You could just use
strchr instead of strtok– Andrew Sun
Nov 13 '18 at 19:11
You could just use
strchr instead of strtok– Andrew Sun
Nov 13 '18 at 19:11
Can't reproduce. coliru.stacked-crooked.com/a/913d3de1fdad058a
– SergeyA
Nov 13 '18 at 19:13
Can't reproduce. coliru.stacked-crooked.com/a/913d3de1fdad058a
– SergeyA
Nov 13 '18 at 19:13
add a comment |
2 Answers
2
active
oldest
votes
Your second strtok() should not use = as the delimiter. You would only do that if there were another = that ended the value. But the value ends at the end of the string. Use an empty delimiter for this part.
key = strtok(aux, "=");
value = strtok(NULL, "");
answered Nov 13 '18 at 19:24
BarmarBarmar
423k35244346
Thanks! It works prefectly.
– Tony Ceralva
Nov 13 '18 at 19:43
add a comment |
strtok is probably overkill (and non-reentrant) when it's just one token. This will do,
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
int main(int argc, char **argv) {
char *key, *equals, *value;
if(argc != 2 || !(equals = strchr(key = argv[1], '=')))
return fprintf(stderr, "KEY=VALUEn"), EXIT_FAILURE;
value = equals + 1;
*equals = '';
printf("key: <%s>; value: <%s>.n", key, value);
return EXIT_SUCCESS;
}
Although strtok is probably easier to read. One may try strsep, but it is GNU C.
answered Nov 13 '18 at 19:44
Neil EdelmanNeil Edelman
42228
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
Your second strtok() should not use = as the delimiter. You would only do that if there were another = that ended the value. But the value ends at the end of the string. Use an empty delimiter for this part.
key = strtok(aux, "=");
value = strtok(NULL, "");
answered Nov 13 '18 at 19:24
BarmarBarmar
423k35244346
Thanks! It works prefectly.
– Tony Ceralva
Nov 13 '18 at 19:43
add a comment |
Your second strtok() should not use = as the delimiter. You would only do that if there were another = that ended the value. But the value ends at the end of the string. Use an empty delimiter for this part.
key = strtok(aux, "=");
value = strtok(NULL, "");
answered Nov 13 '18 at 19:24
BarmarBarmar
423k35244346
Thanks! It works prefectly.
– Tony Ceralva
Nov 13 '18 at 19:43
add a comment |
Your second strtok() should not use = as the delimiter. You would only do that if there were another = that ended the value. But the value ends at the end of the string. Use an empty delimiter for this part.
key = strtok(aux, "=");
value = strtok(NULL, "");
answered Nov 13 '18 at 19:24
BarmarBarmar
423k35244346
Your second strtok() should not use = as the delimiter. You would only do that if there were another = that ended the value. But the value ends at the end of the string. Use an empty delimiter for this part.
key = strtok(aux, "=");
value = strtok(NULL, "");
answered Nov 13 '18 at 19:24
BarmarBarmar
423k35244346
answered Nov 13 '18 at 19:24
BarmarBarmar
423k35244346
answered Nov 13 '18 at 19:24
BarmarBarmar
423k35244346
answered Nov 13 '18 at 19:24
BarmarBarmar
423k35244346
423k35244346
Thanks! It works prefectly.
– Tony Ceralva
Nov 13 '18 at 19:43
add a comment |
Thanks! It works prefectly.
– Tony Ceralva
Nov 13 '18 at 19:43
Thanks! It works prefectly.
– Tony Ceralva
Nov 13 '18 at 19:43
Thanks! It works prefectly.
– Tony Ceralva
Nov 13 '18 at 19:43
add a comment |
strtok is probably overkill (and non-reentrant) when it's just one token. This will do,
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
int main(int argc, char **argv) {
char *key, *equals, *value;
if(argc != 2 || !(equals = strchr(key = argv[1], '=')))
return fprintf(stderr, "KEY=VALUEn"), EXIT_FAILURE;
value = equals + 1;
*equals = '';
printf("key: <%s>; value: <%s>.n", key, value);
return EXIT_SUCCESS;
}
Although strtok is probably easier to read. One may try strsep, but it is GNU C.
answered Nov 13 '18 at 19:44
Neil EdelmanNeil Edelman
42228
add a comment |
strtok is probably overkill (and non-reentrant) when it's just one token. This will do,
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
int main(int argc, char **argv) {
char *key, *equals, *value;
if(argc != 2 || !(equals = strchr(key = argv[1], '=')))
return fprintf(stderr, "KEY=VALUEn"), EXIT_FAILURE;
value = equals + 1;
*equals = '';
printf("key: <%s>; value: <%s>.n", key, value);
return EXIT_SUCCESS;
}
Although strtok is probably easier to read. One may try strsep, but it is GNU C.
answered Nov 13 '18 at 19:44
Neil EdelmanNeil Edelman
42228
add a comment |
strtok is probably overkill (and non-reentrant) when it's just one token. This will do,
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
int main(int argc, char **argv) {
char *key, *equals, *value;
if(argc != 2 || !(equals = strchr(key = argv[1], '=')))
return fprintf(stderr, "KEY=VALUEn"), EXIT_FAILURE;
value = equals + 1;
*equals = '';
printf("key: <%s>; value: <%s>.n", key, value);
return EXIT_SUCCESS;
}
Although strtok is probably easier to read. One may try strsep, but it is GNU C.
answered Nov 13 '18 at 19:44
Neil EdelmanNeil Edelman
42228
strtok is probably overkill (and non-reentrant) when it's just one token. This will do,
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
int main(int argc, char **argv) {
char *key, *equals, *value;
if(argc != 2 || !(equals = strchr(key = argv[1], '=')))
return fprintf(stderr, "KEY=VALUEn"), EXIT_FAILURE;
value = equals + 1;
*equals = '';
printf("key: <%s>; value: <%s>.n", key, value);
return EXIT_SUCCESS;
}
Although strtok is probably easier to read. One may try strsep, but it is GNU C.
answered Nov 13 '18 at 19:44
Neil EdelmanNeil Edelman
42228
answered Nov 13 '18 at 19:44
Neil EdelmanNeil Edelman
42228
answered Nov 13 '18 at 19:44
Neil EdelmanNeil Edelman
42228
answered Nov 13 '18 at 19:44
Neil EdelmanNeil Edelman
42228
42228
add a comment |
add a comment |
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You have to write your own parser.
– john elemans
Nov 13 '18 at 19:11
4
You could just use
strchrinstead ofstrtok– Andrew Sun
Nov 13 '18 at 19:11
Can't reproduce. coliru.stacked-crooked.com/a/913d3de1fdad058a
– SergeyA
Nov 13 '18 at 19:13