write-out.d: clarify Windows % symbol escaping #10337

jay · 2023-01-23T08:45:10Z

Clarify that in Windows batch files the % must be escaped as %%, and at the command prompt it cannot be escaped which could lead to incorrect expansion.

Prior to this change the doc implied % must be escaped as %% in win32 always.

Examples:

If curl --write-out "%{http_code}" is executed in a batch file: {http_code}

If curl --write-out "%%{http_code}" is executed in a batch file: %{http_code}

If curl --write-out "%{http_code}" is executed from the command prompt: %{http_code}

If curl --write-out "%%{http_code}" is executed from the command prompt: %%{http_code}

At the command prompt something like "%{speed_download}%{http_code}" would first be parsed by the command interpreter as %{speed_download}% and would be expanded as environment variable {speed_download} if it existed, though that's highly unlikely since Windows environment names don't use braces.

Reported-by: Muhammad Hussein Ammari

Fixes #10323
Closes #xxxx

- Clarify that in Windows batch files the % must be escaped as %%, and at the command prompt it cannot be escaped which could lead to incorrect expansion. Prior to this change the doc implied % must be escaped as %% in win32 always. --- Examples: If curl --write-out "%{http_code}" is executed in a batch file: {http_code} If curl --write-out "%%{http_code}" is executed in a batch file: %{http_code} If curl --write-out "%{http_code}" is executed from the command prompt: %{http_code} If curl --write-out "%%{http_code}" is executed from the command prompt: %%{http_code} At the command prompt something like "%{speed_download}%{http_code}" would first be parsed by the command interpreter as %{speed_download}% and would be expanded as environment variable {speed_download} if it existed, though that's highly unlikely since Windows environment names don't use braces. --- Reported-by: Muhammad Hussein Ammari Fixes curl#10323 Closes #xxxx

- Clarify that in Windows batch files the % must be escaped as %%, and at the command prompt it cannot be escaped which could lead to incorrect expansion. Prior to this change the doc implied % must be escaped as %% in win32 always. --- Examples: If curl --write-out "%{http_code}" is executed in a batch file: {http_code} If curl --write-out "%%{http_code}" is executed in a batch file: %{http_code} If curl --write-out "%{http_code}" is executed from the command prompt: %{http_code} If curl --write-out "%%{http_code}" is executed from the command prompt: %%{http_code} At the command prompt something like "%{speed_download}%{http_code}" would first be parsed by the command interpreter as %{speed_download}% and would be expanded as environment variable {speed_download} if it existed, though that's highly unlikely since Windows environment names don't use braces. --- Reported-by: Muhammad Hussein Ammari Ref: curl/curl#10337 Fixes curl/curl#10323 Closes #xxxx

- Clarify that in Windows batch files the % must be escaped as %%, and at the command prompt it cannot be escaped which could lead to incorrect expansion. Prior to this change the doc implied % must be escaped as %% in win32 always. --- Examples showing how a write-out argument is received by curl: If curl --write-out "%{http_code}" is executed in a batch file: {http_code} If curl --write-out "%%{http_code}" is executed in a batch file: %{http_code} If curl --write-out "%{http_code}" is executed from the command prompt: %{http_code} If curl --write-out "%%{http_code}" is executed from the command prompt: %%{http_code} At the command prompt something like "%{speed_download}%{http_code}" would first be parsed by the command interpreter as %{speed_download}% and would be expanded as environment variable {speed_download} if it existed, though that's highly unlikely since Windows environment names don't use braces. --- Reported-by: Muhammad Hussein Ammari Ref: curl/curl#10337 Fixes curl/curl#10323 Closes #279

- Clarify that in Windows batch files the % must be escaped as %%, and at the command prompt it cannot be escaped which could lead to incorrect expansion. Prior to this change the doc implied % must be escaped as %% in win32 always. --- Examples showing how a write-out argument is received by curl: If curl --write-out "%{http_code}" is executed in a batch file: {http_code} If curl --write-out "%%{http_code}" is executed in a batch file: %{http_code} If curl --write-out "%{http_code}" is executed from the command prompt: %{http_code} If curl --write-out "%%{http_code}" is executed from the command prompt: %%{http_code} At the command prompt something like "%{speed_download}%{http_code}" would first be parsed by the command interpreter as %{speed_download}% and would be expanded as environment variable {speed_download} if it existed, though that's highly unlikely since Windows environment names don't use braces. --- Reported-by: Muhammad Hussein Ammari Ref: curl/everything-curl#279 Fixes #10323 Closes #10337

- Clarify that in Windows batch files the % must be escaped as %%, and at the command prompt it cannot be escaped which could lead to incorrect expansion. Prior to this change the doc implied % must be escaped as %% in win32 always. --- Examples showing how a write-out argument is received by curl: If curl --write-out "%{http_code}" is executed in a batch file: {http_code} If curl --write-out "%%{http_code}" is executed in a batch file: %{http_code} If curl --write-out "%{http_code}" is executed from the command prompt: %{http_code} If curl --write-out "%%{http_code}" is executed from the command prompt: %%{http_code} At the command prompt something like "%{speed_download}%{http_code}" would first be parsed by the command interpreter as %{speed_download}% and would be expanded as environment variable {speed_download} if it existed, though that's highly unlikely since Windows environment names don't use braces. --- Reported-by: Muhammad Hussein Ammari Ref: curl/everything-curl#279 Fixes curl#10323 Closes curl#10337

jay added the documentation label Jan 23, 2023

This was referenced Jan 23, 2023

verbose/writeout.md: clarify Windows % symbol escaping curl/everything-curl#279

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Formatted String #10323

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jay closed this Jan 26, 2023

jay deleted the write-out-win32-batch branch January 26, 2023 23:53

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write-out.d: clarify Windows % symbol escaping #10337

write-out.d: clarify Windows % symbol escaping #10337

jay commented Jan 23, 2023

write-out.d: clarify Windows % symbol escaping #10337

write-out.d: clarify Windows % symbol escaping #10337

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jay commented Jan 23, 2023